Systems and methods for mitigating decoding errors due to puncturing of symbols

ABSTRACT

Aspects of the disclosure relate to techniques for mitigating the decoding errors observed at the receiver as a result of puncturing symbols between consecutive subframes having the same transmission direction. To reduce the decoding errors, a plurality of transmission options, each including a number of resource blocks and a modulation and coding scheme (MCS), may be identified. In addition, each transmission option may be associated with one or more puncturing patterns that hinder decoding of a codeword at the receiver. The base station or user equipment (UE) may then select or modify at least one aspect of a scheduling decision involving the communication of the codeword in a given subframe of at least two consecutive subframes to minimize decoding errors. For example, a selected puncturing pattern or a transport block size associated with a selected transmission option may be modified.

PRIORITY CLAIM

The present Application for Patent is a Continuation of U.S. Pat. No.10,560,220 issued on Feb. 11, 2020, the entire content of which isincorporated herein by reference as if fully set forth below in itsentirety and for all applicable purposes. U.S. Pat. No. 10,560,220claims priority to and the benefit of Indian Application No.201741018048 filed in the Indian Patent Office on May 23, 2017, theentire content of which is incorporated herein by reference as if fullyset forth below in its entirety and for all applicable purposes.

TECHNICAL FIELD

The technology discussed below relates generally to wirelesscommunication systems, and more particularly, to puncturing of symbolswithin subframes.

INTRODUCTION

In a fourth-generation (4G) wireless communication network that followsstandards for an evolved UMTS Terrestrial Radio Access Network (eUTRAN,also commonly known as Long-Term Evolution (LTE)), over-the-airtransmissions of information are assigned to various physical channelsor signals. Very generally, these physical channels or signals carrytraffic and control information. For example, a Physical Downlink SharedChannel (PDSCH) is the main traffic bearing downlink channel, while thePhysical Uplink Shared Channel (PUSCH) is the main traffic bearinguplink channel. Similarly, a Physical Downlink Control Channel (PDCCH)carries downlink control information (DCI) providing downlinkassignments and/or uplink grants of time-frequency resources to a userequipment (UE) or a group of UEs. In addition, a Physical Uplink ControlChannel (PUCCH) carries uplink control information includingacknowledgement information, channel quality information, schedulingrequests and multiple-input-multiple-output (MIMO) feedback information.These channels and signals are time-divided into frames, and the framesare further subdivided into subframes, time slots, and symbols.

Release 13 of LTE, often referred to as LTE-M, introduced a new UEcategory for enhanced machine-type communications (eMTC) that supportsreduced bandwidth, reduced transmit power, lower data rates, longbattery life, and extended coverage operations. These UEs are typicallyreferred to as bandwidth-reduced, low-complexity (BL), coverageenhancement (CE) UE's (or BL/CE UEs). BL/CE UEs may support differentnarrowbands for uplink transmissions. In some examples, a narrowbandrefers to a group of six contiguous resource blocks, each including, forexample, 12 consecutive sub-carriers in the frequency domain. In somecircumstances, a BL/CE UE may utilize different narrowbands inconsecutive uplink subframes. For example, a BL/CE UE may transmit aPUCCH or PUSCH within a first narrowband in one subframe and a PUCCH orPUSCH within a second narrowband in the next subframe. In thissituation, the BL/CE UE will need to perform frequency retuning from thefirst narrowband to the second narrowband between the two consecutiveuplink subframes.

To accommodate the frequency retuning process, a guard period istypically created between the two consecutive uplink subframes bypuncturing one or more symbols at the end of the first subframe and/orthe beginning of the next subframe. However, when puncturing PUSCHsymbols, decoding errors may occur at the receiver depending on thepuncturing pattern utilized. Therefore, mechanisms for mitigating thedecoding errors due to PUSCH symbol puncturing continue to be researchedand developed for Release 14 of LTE and beyond.

BRIEF SUMMARY OF SOME EXAMPLES

The following presents a simplified summary of one or more aspects ofthe present disclosure, in order to provide a basic understanding ofsuch aspects. This summary is not an extensive overview of allcontemplated features of the disclosure, and is intended neither toidentify key or critical elements of all aspects of the disclosure norto delineate the scope of any or all aspects of the disclosure. Its solepurpose is to present some concepts of one or more aspects of thedisclosure in a simplified form as a prelude to the more detaileddescription that is presented later.

Various aspects of the disclosure provide techniques for mitigating thedecoding errors observed at the receiver as a result of puncturingsymbols between consecutive subframes having the same transmissiondirection. To reduce the decoding errors, a plurality of transmissionoptions, each including a number of resource blocks and a modulation andcoding scheme (MCS), may be identified. In addition, each transmissionoption may be associated with one or more puncturing patterns thathinder decoding of a codeword at the receiver. The base station or userequipment (UE) may then select or modify at least one aspect of ascheduling decision involving the communication of the codeword in agiven subframe of at least two consecutive subframes to minimizedecoding errors. For example, a selected puncturing pattern or atransport block size associated with a selected transmission option maybe modified.

In some examples, the base station may avoid selecting any of thetransmission options and associated puncturing patterns that may hinderdecoding at the receiver when making the scheduling decision forcommunication of the codeword in the given subframe. In other examples,the base station may take into account an impact on subframe N−1 whenmaking a scheduling decision on subframe N. For example, the basestation may modify a narrowband scheduled for subframe N to match thenarrowband scheduled for subframe N−1 to prevent puncturing of thesymbols in subframe N−1 and/or subframe N. As another example, the basestation may simply cancel scheduling of communication of a codeword insubframe N for the UE.

In some examples, the UE or base station may modify the puncturingpattern to puncture different or fewer symbols within the twoconsecutive subframes. In other examples, the UE or base station maymodify the transport block size as a function of the selectedtransmission option and puncturing pattern. For example, a transportblock size table maintained at the UE or base station may be modifiedfor the problematic transmission options (e.g., number of resourceblocks and MCS that may produce decoding errors based on the puncturingpattern).

In other aspects of the disclosure, the base station or UE may utilize aturbo decoder to try different combinations of the punctured bits thatresult in a cyclic redundancy code (CRC) pass to attempt to decode thepunctured subframe(s). The base station or UE may further run a Viterbialgorithm utilizing the tail bits in the trellis termination of theturbo code to obtain the punctured bits that result in the correcttermination.

In one aspect of the disclosure, a method of wireless communication at ascheduling entity in a wireless communication network is provided. Themethod includes identifying a plurality of transmission options, eachincluding a respective number of resource blocks and a respectivemodulation and coding scheme (MCS). The method further includesidentifying respective puncturing patterns associated with each of theplurality of transmission options for at least two consecutivesubframes, each having a same transmission direction. The method furtherincludes making a scheduling decision for the at least two consecutivesubframes based on the plurality of transmission options and thepuncturing patterns associated with each of the plurality oftransmission options. The scheduling decision includes at least aselected transmission option of the plurality of transmission optionsfor communication of a first codeword between the scheduling entity anda user equipment (UE) in a given subframe of the at least twoconsecutive subframes. In addition, making the scheduling decisionfurther includes selecting at least one aspect of the schedulingdecision to reduce decoding errors of the first codeword.

Another aspect of the disclosure provides a scheduling entity in awireless communication network. The scheduling entity includes aprocessor, a memory communicatively coupled to the process, and atransceiver communicatively coupled to the processor. The processor isconfigured to identify a plurality of transmission options, eachincluding a respective number of resource blocks and a respectivemodulation and coding scheme (MCS). The processor is further configuredto identify respective puncturing patterns associated with each of theplurality of transmission options for at least two consecutivesubframes, each having a same transmission direction. The processor isconfigured to make a scheduling decision for the at least twoconsecutive subframes based on the plurality of transmission options andthe puncturing patterns associated with each of the plurality oftransmission options. The scheduling decision includes at least aselected transmission option of the plurality of transmission optionsfor communication of a first codeword between the scheduling entity anda user equipment (UE) via the transceiver in a given subframe of the atleast two consecutive subframes. The processor is further configured toselect at least one aspect of the scheduling decision to reduce decodingerrors of the first codeword.

Another aspect of the disclosure provides a method of wirelesscommunication at a scheduled entity in wireless communication with ascheduling entity in a wireless communication network. The methodincludes identifying a plurality of transmission options, each includinga respective number of resource blocks and a respective modulation andcoding scheme (MCS). The method further includes identifying respectivepuncturing patterns associated with each of the plurality oftransmission options for at least two consecutive subframes, each havinga same transmission direction. The method further includes modifying atleast one aspect of a scheduling decision associated with communicationof a codeword between the scheduling entity and the scheduled entity ina given subframe of the at least two consecutive subframes utilizing aselected transmission option of the plurality of transmission options toreduce decoding errors of the codeword. The at least one aspect includesat least one of a selected puncturing pattern of the respectivepuncturing patterns associated with the selected transmission option ora transport block size associated with the codeword.

Another aspect of the disclosure provides user equipment in wirelesscommunication with a scheduling entity within a wireless communicationnetwork. The user equipment includes a processor, a memorycommunicatively coupled to the processor, and a transceivercommunicatively coupled to the processor. The processor is configured toidentify a plurality of transmission options, each including arespective number of resource blocks and a respective modulation andcoding scheme (MCS). The processor is further configured to identifyrespective puncturing patterns associated with each of the plurality oftransmission options for at least two consecutive subframes, each havinga same transmission direction. The processor is further configured tomodify at least one aspect of a scheduling decision associated withcommunication of a codeword between the scheduling entity and thescheduled entity via the transceiver in a given subframe of the at leasttwo consecutive subframes utilizing a selected transmission option ofthe plurality of transmission options to reduce decoding errors of thecodeword. The at least one aspect includes at least one of a selectedpuncturing pattern of the respective puncturing patterns associated withthe selected transmission option or a transport block size associatedwith the codeword.

These and other aspects of the invention will become more fullyunderstood upon a review of the detailed description, which follows.Other aspects, features, and embodiments of the present invention willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific, exemplary embodiments of thepresent invention in conjunction with the accompanying figures. Whilefeatures of the present invention may be discussed relative to certainembodiments and figures below, all embodiments of the present inventioncan include one or more of the advantageous features discussed herein.In other words, while one or more embodiments may be discussed as havingcertain advantageous features, one or more of such features may also beused in accordance with the various embodiments of the inventiondiscussed herein. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a wireless communication system.

FIG. 2 is a conceptual illustration of an example of a radio accessnetwork.

FIG. 3 is a schematic illustration of wireless communication between afirst wireless communication device and a second wireless communicationdevice.

FIG. 4 is a schematic illustration of a comparison of orthogonalfrequency division multiplexing (OFDM) and single-carrier frequencydivision multiplexing (SC-FDM) as may be implemented within a radioaccess network.

FIG. 5 is a conceptual diagram illustrating an example of a radioprotocol architecture for the user and control planes.

FIG. 6 is a conceptual diagram illustrating the transmission of atransport block within a frame.

FIG. 7 is a conceptual diagram illustrating two consecutive uplinksubframes implementing a guard period for frequency retuning between thesubframes, in accordance with aspects of the present disclosure.

FIG. 8 is a table illustrating examples of combinations of MCS index andnumber of RB s for which a puncturing pattern of PUSCH symbols hindersdecoding at the base station, in accordance with aspects of the presentdisclosure.

FIG. 9 is a block diagram illustrating an example of a hardwareimplementation for a scheduling entity apparatus employing a processingsystem in accordance with aspects of the present disclosure.

FIG. 10 is a block diagram illustrating an example of a hardwareimplementation for a scheduled entity apparatus employing a processingsystem in accordance with aspects of the present disclosure.

FIG. 11 is a table illustrating examples of combinations of MCS indexand number of RB s for which a modified transport block size reduces thedecoding errors at the receiver, in accordance with aspects of thepresent disclosure.

FIG. 12 is a flow chart illustrating an exemplary process for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the disclosure.

FIG. 13 is a flow chart illustrating another exemplary process for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the disclosure.

FIG. 14 is a flow chart illustrating another exemplary process for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the disclosure.

FIG. 15 is a flow chart illustrating another exemplary process for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the disclosure.

FIG. 16 is a flow chart illustrating an exemplary process for ascheduled entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the disclosure.

FIG. 17 is a flow chart illustrating another exemplary process for ascheduled entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

While aspects and embodiments are described in this application byillustration to some examples, those skilled in the art will understandthat additional implementations and use cases may come about in manydifferent arrangements and scenarios. Innovations described herein maybe implemented across many differing platform types, devices, systems,shapes, sizes, packaging arrangements. For example, embodiments and/oruses may come about via integrated chip embodiments and othernon-module-component based devices (e.g., end-user devices, vehicles,communication devices, computing devices, industrial equipment,retail/purchasing devices, medical devices, AI-enabled devices, etc.).While some examples may or may not be specifically directed to use casesor applications, a wide assortment of applicability of describedinnovations may occur. Implementations may range a spectrum fromchip-level or modular components to non-modular, non-chip-levelimplementations and further to aggregate, distributed, or OEM devices orsystems incorporating one or more aspects of the described innovations.In some practical settings, devices incorporating described aspects andfeatures may also necessarily include additional components and featuresfor implementation and practice of claimed and described embodiments.For example, transmission and reception of wireless signals necessarilyincludes a number of components for analog and digital purposes (e.g.,hardware components including antenna, RF-chains, power amplifiers,modulators, buffer, processor(s), interleaver, adders/summers, etc.). Itis intended that innovations described herein may be practiced in a widevariety of devices, chip-level components, systems, distributedarrangements, end-user devices, etc. of varying sizes, shapes andconstitution.

The various concepts presented throughout this disclosure may beimplemented across a broad variety of telecommunication systems, networkarchitectures, and communication standards. Referring now to FIG. 1, asan illustrative example without limitation, various aspects of thepresent disclosure are illustrated with reference to a wirelesscommunication system 100. The wireless communication system 100 includesthree interacting domains: a core network 102, a radio access network(RAN) 104, and a user equipment (UE) 106. By virtue of the wirelesscommunication system 100, the UE 106 may be enabled to carry out datacommunication with an external data network 110, such as (but notlimited to) the Internet.

The RAN 104 may implement any suitable wireless communication technologyor technologies to provide radio access to the UE 106. As one example,the RAN 104 may operate according to 3rd Generation Partnership Project(3GPP) Evolved Universal Terrestrial Radio Access Network (eUTRAN)standards, often referred to as Long-Term Evolution (LTE) or 4G. In someexamples, the RAN 104 may operate according to Release 13 or later ofLTE standards. Of course, many other examples may be utilized within thescope of the present disclosure.

As illustrated, the RAN 104 includes a plurality of base stations 108.Broadly, a base station is a network element in a radio access networkresponsible for radio transmission and reception in one or more cells toor from a UE. In different technologies, standards, or contexts, a basestation may variously be referred to by those skilled in the art as abase transceiver station (BTS), a radio base station, a radiotransceiver, a transceiver function, a basic service set (BSS), anextended service set (ESS), an access point (AP), a Node B (NB), aneNode B (eNB), or some other suitable terminology.

The radio access network 104 is further illustrated supporting wirelesscommunication for multiple mobile apparatuses. A mobile apparatus may bereferred to as user equipment (UE) in 3GPP standards, but may also bereferred to by those skilled in the art as a mobile station (MS), asubscriber station, a mobile unit, a subscriber unit, a wireless unit, aremote unit, a mobile device, a wireless device, a wirelesscommunications device, a remote device, a mobile subscriber station, anaccess terminal (AT), a mobile terminal, a wireless terminal, a remoteterminal, a handset, a terminal, a user agent, a mobile client, aclient, or some other suitable terminology. A UE may be an apparatusthat provides a user with access to network services. In accordance withvarious aspects of the present disclosure, a UE may further include anenhanced machine-type communications (eMTC) device that supports reducedbandwidth, reduced transmit power, lower data rates, long battery life,and extended coverage operations. These UEs may be referred to herein asbandwidth-reduced, low-complexity (BL), coverage enhancement (CE) UEs(or BL/CE UEs).

Within the present document, a “mobile” apparatus need not necessarilyhave a capability to move, and may be stationary. The term mobileapparatus or mobile device broadly refers to a diverse array of devicesand technologies. UEs may include a number of hardware structuralcomponents sized, shaped, and arranged to help in communication; suchcomponents can include antennas, antenna arrays, RF chains, amplifiers,one or more processors, etc. electrically coupled to each other. Forexample, some non-limiting examples of a mobile apparatus include amobile, a cellular (cell) phone, a smart phone, a session initiationprotocol (SIP) phone, a laptop, a personal computer (PC), a notebook, anetbook, a smartbook, a tablet, a personal digital assistant (PDA), anda broad array of embedded systems, e.g., corresponding to an “Internetof Things” (IoT). A mobile apparatus may additionally be an automotiveor other transportation vehicle, a remote sensor or actuator, a robot orrobotics device, a satellite radio, a global positioning system (GPS)device, an object tracking device, a drone, a multi-copter, aquad-copter, a remote control device, a consumer and/or wearable device,such as eyewear, a wearable camera, a virtual reality device, a smartwatch, a health or fitness tracker, a digital audio player (e.g., MP3player), a camera, a game console, etc. A mobile apparatus mayadditionally be a digital home or smart home device such as a homeaudio, video, and/or multimedia device, an appliance, a vending machine,intelligent lighting, a home security system, a smart meter, etc. Amobile apparatus may additionally be a smart energy device, a securitydevice, a solar panel or solar array, a municipal infrastructure devicecontrolling electric power (e.g., a smart grid), lighting, water, etc.;an industrial automation and enterprise device; a logistics controller;agricultural equipment; military defense equipment, vehicles, aircraft,ships, and weaponry, etc. Still further, a mobile apparatus may providefor connected medicine or telemedicine support, i.e., health care at adistance. Telehealth devices may include telehealth monitoring devicesand telehealth administration devices, whose communication may be givenpreferential treatment or prioritized access over other types ofinformation, e.g., in terms of prioritized access for transport ofcritical service data, and/or relevant QoS for transport of criticalservice data.

Wireless communication between a RAN 104 and a UE 106 may be describedas utilizing an air interface. Transmissions over the air interface froma base station (e.g., base station 108) to one or more UEs (e.g., UE106) may be referred to as downlink (DL) transmission. In accordancewith certain aspects of the present disclosure, the term downlink mayrefer to a point-to-multipoint transmission originating at a schedulingentity (described further below; e.g., base station 108). Another way todescribe this scheme may be to use the term broadcast channelmultiplexing. Transmissions from a UE (e.g., UE 106) to a base station(e.g., base station 108) may be referred to as uplink (UL)transmissions. In accordance with further aspects of the presentdisclosure, the term uplink may refer to a point-to-point transmissionoriginating at a scheduled entity (described further below; e.g., UE106).

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station 108) allocates resources forcommunication among some or all devices and equipment within its servicearea or cell. Within the present disclosure, as discussed further below,the scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more scheduledentities. That is, for scheduled communication, UEs 106, which may bescheduled entities, may utilize resources allocated by the schedulingentity 108.

Base stations 108 are not the only entities that may function asscheduling entities. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more scheduledentities (e.g., one or more other UEs).

As illustrated in FIG. 1, a scheduling entity 108 may transmit downlinktraffic 112 to one or more scheduled entities 106. Broadly, thescheduling entity 108 is a node or device responsible for schedulingtraffic in a wireless communication network, including the downlinktraffic 112 and, in some examples, uplink traffic 116 from one or morescheduled entities 106 to the scheduling entity 108. On the other hand,the scheduled entity 106 is a node or device that receives downlinkcontrol information 114, including but not limited to schedulinginformation (e.g., a grant), synchronization or timing information, orother control information from another entity in the wirelesscommunication network such as the scheduling entity 108.

For example, the scheduling entity 108 may transmit control information114 including one or more control channels, such as a PBCH; a PSS; aSSS; a physical control format indicator channel (PCFICH); a physicalhybrid automatic repeat request (HARQ) indicator channel (PHICH); and/ora physical downlink control channel (PDCCH), etc., to one or morescheduled entities 106. The PHICH carries HARQ feedback transmissionssuch as an acknowledgment (ACK) or negative acknowledgment (NACK). HARQis a technique well-known to those of ordinary skill in the art, whereinpacket transmissions may be checked at the receiving side for accuracy,and if confirmed, an ACK may be transmitted, whereas if not confirmed, aNACK may be transmitted. In response to a NACK, the transmitting devicemay send a HARQ retransmission, which may implement chase combining,incremental redundancy, etc.

Uplink traffic 116 and/or downlink traffic 112 including one or moretraffic channels, such as a physical downlink shared channel (PDSCH) ora physical uplink shared channel (PUSCH) (and, in some examples, systeminformation blocks (SIBs)), may additionally be transmitted between thescheduling entity 108 and the scheduled entities 106. Furthermore, thescheduled entities 106 may transmit uplink control information 118including one or more uplink control channels, such as a physical uplinkcontrol channel (PUCCH), to the scheduling entity 108. Uplink controlinformation may include a variety of packet types and categories,including pilots, reference signals, and information configured toenable or assist in decoding uplink traffic transmissions. In someexamples, the uplink control information 118 may include a schedulingrequest (SR), i.e., request for the scheduling entity 108 to schedule anuplink packet transmission for a scheduled entity 106. Here, in responseto the SR transmitted on an uplink control channel 118, the schedulingentity 108 may transmit downlink control information 114 to thescheduled entity 106 that may schedule the uplink packet transmission.

In addition, the uplink and/or downlink control information and/ortraffic information may be time-divided into frames, subframes, timeslots, and/or symbols. As used herein, a symbol may refer to a unit oftime that, in an orthogonal frequency division multiplexed (OFDM)waveform, carries one resource element (RE) per sub-carrier. A time slotmay carry 7 OFDM symbols with normal cyclic prefix (CP). A subframe mayrefer to a duration of 1 ms, and in some examples, may include two timeslots. Multiple subframes may be grouped together to form a single frameor radio frame. For example, a frame may include ten equally sizedsubframes. Of course, these definitions are not required, and anysuitable scheme for organizing waveforms may be utilized, and varioustime divisions of the waveform may have any suitable duration.

In general, base stations 108 may include a backhaul interface forcommunication with a backhaul portion 120 of the wireless communicationsystem. The backhaul 120 may provide a link between a base station 108and the core network 102. Further, in some examples, a backhaul networkmay provide interconnection between the respective base stations 108.Various types of backhaul interfaces may be employed, such as a directphysical connection, a virtual network, or the like using any suitabletransport network.

The core network 102 may be a part of the wireless communication system100, and may be independent of the radio access technology used in theRAN 104. In some examples, the core network 102 may be configuredaccording to a 4G evolved packet core (EPC), or any other suitablestandard or configuration.

Referring now to FIG. 2, by way of example and without limitation, aschematic illustration of a RAN 200 is provided. In some examples, theRAN 200 may be the same as the RAN 104 described above and illustratedin FIG. 1. The geographic area covered by the RAN 200 may be dividedinto cellular regions (cells) that can be uniquely identified by a userequipment (UE) based on an identification broadcasted from one accesspoint or base station. FIG. 2 illustrates macrocells 202, 204, and 206,and a small cell 208, each of which may include one or more sectors (notshown). A sector is a sub-area of a cell. All sectors within one cellare served by the same base station. A radio link within a sector can beidentified by a single logical identification belonging to that sector.In a cell that is divided into sectors, the multiple sectors within acell can be formed by groups of antennas with each antenna responsiblefor communication with UEs in a portion of the cell.

In FIG. 2, two base stations 210 and 212 are shown in cells 202 and 204;and a third base station 214 is shown controlling a remote radio head(RRH) 216 in cell 206. That is, a base station can have an integratedantenna or can be connected to an antenna or RRH by feeder cables. Inthe illustrated example, the cells 202, 204, and 126 may be referred toas macrocells, as the base stations 210, 212, and 214 support cellshaving a large size. Further, a base station 218 is shown in the smallcell 208 (e.g., a microcell, picocell, femtocell, home base station,home Node B, home eNode B, etc.) which may overlap with one or moremacrocells. In this example, the cell 208 may be referred to as a smallcell, as the base station 218 supports a cell having a relatively smallsize. Cell sizing can be done according to system design as well ascomponent constraints.

It is to be understood that the radio access network 200 may include anynumber of wireless base stations and cells. Further, a relay node may bedeployed to extend the size or coverage area of a given cell. The basestations 210, 212, 214, 218 provide wireless access points to a corenetwork for any number of mobile apparatuses. In some examples, the basestations 210, 212, 214, and/or 218 may be the same as the basestation/scheduling entity 108 described above and illustrated in FIG. 1.

Within the RAN 200, the cells may include UEs that may be incommunication with one or more sectors of each cell. Further, each basestation 210, 212, 214, and 218 may be configured to provide an accesspoint to a core network 102 (see FIG. 1) for all the UEs in therespective cells. For example, UEs 222 and 224 may be in communicationwith base station 210; UEs 226 and 228 may be in communication with basestation 212; UEs 230 and 232 may be in communication with base station214 by way of RRH 216; and UE 234 may be in communication with basestation 218. In some examples, the UEs 222, 224, 226, 228, 230, 232,234, 238, 240, and/or 242 may be the same as the UE/scheduled entity 106described above and illustrated in FIG. 1.

In some examples, an unmanned aerial vehicle (UAV) 220, which may be adrone or quadcopter, can be a mobile network node and may be configuredto function as a UE. For example, the UAV 220 may operate within cell202 by communicating with base station 210.

In a further aspect of the RAN 200, sidelink signals may be used betweenUEs without necessarily relying on scheduling or control informationfrom a base station. For example, two or more UEs (e.g., UEs 226 and228) may communicate with each other using peer to peer (P2P) orsidelink signals 227 without relaying that communication through a basestation (e.g., base station 212). In a further example, UE 238 isillustrated communicating with UEs 240 and 242. Here, the UE 238 mayfunction as a scheduling entity or a primary sidelink device, and UEs240 and 242 may function as a scheduled entity or a non-primary (e.g.,secondary) sidelink device.

In the radio access network 200, the ability for a UE to communicatewhile moving, independent of its location, is referred to as mobility.The various physical channels between the UE and the radio accessnetwork are generally set up, maintained, and released under the controlof a mobility management entity (MME). In various aspects of thedisclosure, a radio access network 200 may utilize DL-based mobility toenable mobility and handovers (i.e., the transfer of a UE's connectionfrom one radio channel to another). In a network configured for DL-basedmobility, during a call with a scheduling entity, or at any other time,a UE may monitor various parameters of the signal from its serving cellas well as various parameters of neighboring cells. Depending on thequality of these parameters, the UE may maintain communication with oneor more of the neighboring cells. During this time, if the UE moves fromone cell to another, or if signal quality from a neighboring cellexceeds that from the serving cell for a given amount of time, the UEmay undertake a handoff or handover from the serving cell to theneighboring (target) cell. For example, UE 224 (illustrated as avehicle, although any suitable form of UE may be used) may move from thegeographic area corresponding to its serving cell 202 to the geographicarea corresponding to a neighbor cell 206. When the signal strength orquality from the neighbor cell 206 exceeds that of its serving cell 202for a given amount of time, the UE 224 may transmit a reporting messageto its serving base station 210 indicating this condition. In response,the UE 224 may receive a handover command, and the UE may undergo ahandover to the cell 206.

In various implementations, the air interface in the radio accessnetwork 200 may utilize licensed spectrum, unlicensed spectrum, orshared spectrum. Licensed spectrum provides for exclusive use of aportion of the spectrum, generally by virtue of a mobile networkoperator purchasing a license from a government regulatory body.Unlicensed spectrum provides for shared use of a portion of the spectrumwithout need for a government-granted license. While compliance withsome technical rules is generally still required to access unlicensedspectrum, generally, any operator or device may gain access. Sharedspectrum may fall between licensed and unlicensed spectrum, whereintechnical rules or limitations may be required to access the spectrum,but the spectrum may still be shared by multiple operators and/ormultiple RATs. For example, the holder of a license for a portion oflicensed spectrum may provide licensed shared access (LSA) to share thatspectrum with other parties, e.g., with suitable licensee-determinedconditions to gain access.

The air interface in the radio access network 200 may utilize one ormore multiplexing and multiple access algorithms to enable simultaneouscommunication of the various devices. For example, multiple access forUL transmissions from UEs 222 and 224 to base station 210 may beprovided utilizing time division multiple access (TDMA), code divisionmultiple access (CDMA), frequency division multiple access (FDMA),orthogonal frequency division multiple access (OFDMA), sparse codemultiple access (SCMA), single-carrier frequency division multipleaccess (SC-FDMA), resource spread multiple access (RSMA), or othersuitable multiple access schemes. Further, multiplexing DL transmissionsfrom the base station 210 to UEs 222 and 224 may be provided utilizingtime division multiplexing (TDM), code division multiplexing (CDM),frequency division multiplexing (FDM), orthogonal frequency divisionmultiplexing (OFDM), sparse code multiplexing (SCM), single-carrierfrequency division multiplexing (SC-FDM), or other suitable multiplexingschemes.

The air interface in the radio access network 200 may further utilizeone or more duplexing algorithms. Duplex refers to a point-to-pointcommunication link where both endpoints can communicate with one anotherin both directions. Full duplex means both endpoints can simultaneouslycommunicate with one another. Half duplex means only one endpoint cansend information to the other at a time. In a wireless link, a fullduplex channel generally relies on physical isolation of a transmitterand receiver, and suitable interference cancellation technologies. Fullduplex emulation is frequently implemented for wireless links byutilizing frequency division duplex (FDD) or time division duplex (TDD).In FDD, transmissions in different directions operate at differentcarrier frequencies. In TDD, transmissions in different directions on agiven channel are separated from one another using time divisionmultiplexing. That is, at some times the channel is dedicated fortransmissions in one direction, while at other times the channel isdedicated for transmissions in the other direction, where the directionmay change very rapidly, e.g., several times per slot.

In order for transmissions over the radio access network 200 to obtain alow block error rate (BLER) while still achieving very high data rates,channel coding may be used. That is, wireless communication maygenerally utilize a suitable error correcting code. In a typical errorcorrecting code, an encoder (e.g., a CODEC) at the transmitting devicemathematically adds redundancy to an information message. Exploitationof this redundancy in the encoded information message can improve thereliability of the message, enabling correction for any bit errors thatmay occur due to the noise.

FIG. 3 is a schematic illustration of wireless communication between afirst wireless communication device 302 and a second wirelesscommunication device 304. Each wireless communication device 302 and 304may be a user equipment (UE), a base station, or any other suitableapparatus or means for wireless communication. In the illustratedexample, a source 322 within the first wireless communication device 302transmits a digital message over a communication channel 306 (e.g., awireless channel) to a sink 344 in the second wireless communicationdevice 304. One issue in such a scheme that must be addressed to providefor reliable communication of the digital message, is to take intoaccount the noise 308 that affects the communication channel 306.

Error correcting codes are frequently used to provide reliabletransmission of digital messages over such noisy channels. Examples oferror correcting codes include block codes and convolutional codes.Convolutional codes convert the entire information message or sequenceinto a single codeword or code block, where the encoded bits depend notonly on current information bits in the information message, but also onpast information bits in the information message, thus providingredundancy.

For example, an encoder 324 at the first (transmitting) wirelesscommunication device 302 may use a sliding window to calculate paritybits by combining various subsets of the information bits in the window.The calculated parity bits may then be transmitted over the channel.Exploitation of the redundancy provided by the parity bits is the key toreliability of the message, enabling correction for any bit errors thatmay occur due to the noise. As an example, if a convolutional codeproduces r parity bits per window and slides the window forward by onebit at a time, its rate is 1/r. Since the parity bits are the only bitstransmitted, the greater the value of r, the greater the resilience tobit errors. That is, a decoder 342 at the second (receiving) wirelesscommunication device 304 can take advantage of the redundancy providedby the parity bits to reliably recover the information message eventhough bit errors may occur, in part, due to the addition of noise 308to the channel.

Block codes split the information message up into blocks, each blockhaving a length of K information bits. The encoder 324 at the first(transmitting) wireless communication device 302 then mathematicallyadds redundancy (e.g., parity bits) to the information message,resulting in codewords or code blocks having a length of N, where N>K.Here, the code rate R is the ratio between the message length and theblock length: i.e., R=K/N. Thus, with block codes, the information bitsare transmitted together with the parity bits. That is, the decoder 342at the second (receiving) wireless communication device 304 can takeadvantage of the redundancy provided by the parity bits to reliablyrecover the information message even though bit errors may occur, inpart, due to the addition of noise 308 to the channel.

Many examples of such error correcting block codes are known to those ofordinary skill in the art, including Hamming codes,Bose-Chaudhuri-Hocquenghem (BCH) codes, turbo codes, polar codes, andlow-density parity check (LDPC) codes, among others. Many existingwireless communication networks utilize such block codes, such as 3GPPLTE networks, which utilize turbo codes; and IEEE 802.11n Wi-Finetworks, which utilize LDPC codes.

Turbo codes are a class of convolutional codes that appear similar tolinear block codes. A turbo code includes a parallel concatenation of anumber of recursive systematic convolutional (RSC) coders. Typically,the number of RSC coders is kept low (e.g., two) to maximize theperformance, while minimizing the complexity. An RSC coder takes asinput systematic (information) bits x and outputs the systematic bits xand parity bits p₁. The parity bits p₁ are generated by combiningvarious subsets of the systematic bits in the sliding window and foldingback one of the output sequences to the coder input, thus making thecoder recursive. When using two RSC coders for a turbo encoder 324, theinput to the second RSC coder is typically an interleaved version of thesystematic bits x, thus producing a second set of parity bits p₂. Thetwo sets of parity bits p₁ and p₂ may thus be considered time displacedcodes generated from the same input sequence x. The output of the turboencoder 324 is then the systematic bits x, multiplexed together with thetwo sets of parity bits p₁ and p₂.

At the receiving wireless communication device 304, the signal isdemodulated with its associated noise and a soft output for each bit maybe provided to a turbo decoder 342. The soft output is typically the loglikelihood ratio (LLR), which is a measure of the probability that,given a received soft input y′, the message bit m, associated with atransition in the trellis is 1 or 0. If it is equiprobable that themessage bit is a 1 or 0, then the LLR is 0.

The soft values of the information sequence x′, and the soft values ofthe parity bits p₁′ and p₂′ may be utilized to initialize the turbodecoder 342, which typically includes two decoders. The soft values ofparity bits p₁′ and p₂′ may be interleaved and provided to the seconddecoder, while the soft values of the information sequence x′ may beprovided to the first decoder. The sequence derived by the first decodermay be interleaved and presented to the second decoder. Thisre-sequences bits from streams x′ and p′, so that bits generated fromthe same bit in x may be presented simultaneously to the second decoder,whether from x′, p₁′, or p₂′.

In some examples, the decoder 342 may have some knowledge of theprobability of the transmitted signal (e.g., the decoder 342 may knowthat some information messages are more likely than others). This apriori information may assist the turbo decoder 342 in forming the aposteriori output, which represents a best estimate of the receivedinformation sequence x. The a posteriori output is then de-interleavedand presented back to the first decoder. Further iterations through thefirst decoder, interleaver, second decoder, and de-interleaver mayrefine the estimate until a final version of the information sequence ispresented at the output.

The two main types of decoding algorithms utilized by the first andsecond decoders include the Bahl-Cocke-Jelinek-Raviv (BCJR) decodingalgorithm, which is a maximum a posteriori (MAP) algorithm, and the softoutput Viterbi algorithm (SOVA). In general, the MAP algorithm attemptsto estimate the most likely symbol received, while SOVA attempts toestimate the most likely sequence. For example, the MAP algorithmestimates the most probable value for each received bit by calculatingthe conditional probability of the transition from the previous bit,given the probability of the received bit (e.g., as determined by thecomputed LLR). SOVA is similar to the standard Viterbi algorithm in thatSOVA utilizes a trellis to establish a surviving path, but unlike thestandard Viterbi algorithm, SOVA compares the surviving path sequence tothe sequences used to establish non-surviving paths to determine thelikelihood of the surviving path sequence. After a prescribed number ofiterations, the sequence with the maximum likelihood is output from theturbo decoder 342.

FIG. 4 is a schematic illustration of a comparison of orthogonalfrequency division multiplexing (OFDM) and single-carrier frequencydivision multiplexing (SC-FDM) as may be implemented within a radioaccess network, such as the RAN 200 illustrated in FIG. 2. In someexamples, this illustration may represent wireless resources as they maybe allocated in an OFDM or SC-FDM system.

In an OFDM system, a two-dimensional grid of resource elements (REs) maybe defined by separation of frequency resources into closely spacednarrowband frequency tones or sub-carriers, and separation of timeresources into a sequence of OFDM symbols having a given duration. Inthe example shown in FIG. 4, each RE is represented by a rectanglehaving the dimensions of one sub-carrier (e.g., 15 kHz bandwidth) by oneOFDM symbol.

Thus, each RE represents a sub-carrier modulated for the OFDM symbolperiod by one OFDM data symbol. Each OFDM symbol may be modulated using,for example, quadrature phase shift keying (QPSK), 16 quadratureamplitude modulation (QAM) or 64 QAM. For simplicity, only foursub-carriers over two OFDM symbol periods are illustrated. However, itshould be understood that any number of sub-carriers and OFDM symbolperiods may be utilized within a subframe. For example, in LTE networks,a subframe includes two time slots, each including multiple resourceblocks (RBs). A resource block (RB) represents the smallest unit ofresources that may be allocated to a user equipment (UE). Each of theRBs is 180 kHz wide in frequency and one time slot long in time. Forexample, each RB may include 12 consecutive sub-carriers in thefrequency domain and, for a normal cyclic prefix in each OFDM symbol, 7consecutive OFDM symbols in the time domain, or 84 resource elements.

After each OFDM symbol period, respective cyclic prefixes (CPs) may beinserted for each sub-carrier and the next four OFDM symbols may betransmitted in parallel. The CP operates as a guard band between OFDMsymbols and is typically generated by copying a small part of the end ofan OFDM symbol to the beginning of the OFDM symbol.

By setting the spacing between the tones based on the symbol rate,inter-symbol interference can be eliminated. OFDM channels support highdata rates by allocating a data stream in a parallel manner acrossmultiple sub-carriers. However, OFDM suffers from high peak-to-averagepower ratio (PAPR), which can make OFDM undesirable on the uplink, whereUE (scheduled entity) transmit power efficiency and amplifier cost areimportant factors.

In an SC-FDM system, a two-dimensional grid of resource elements (REs)may be defined by utilizing a wider bandwidth single carrier frequency,and separating the time resources into a sequence of SC-FDM symbolshaving a given duration. In the example shown in FIG. 4, a 60 kHzcarrier is shown corresponding to the four 15 kHz sub-carriers in theOFDM system. In addition, although the OFDM and SC-FDM symbols have thesame duration, each SC-FDM symbol contains N “Sub-Symbols” thatrepresent the modulated data symbols. Thus, in the example shown in FIG.4 with four modulated data symbols, in the OFDM system, the fourmodulated data symbols are transmitted in parallel (one persub-carrier), while in the SC-FDM system, the four modulated datasymbols are transmitted in series at four times the rate, with each datasymbol occupying 4×15 kHz bandwidth. Thus, each RE in the SC-FDM systemrepresents the single carrier frequency modulated for the Sub-Symbolperiod by one SC-FDM data symbol.

By transmitting the N data symbols in series at N times the rate, theSC-FDM bandwidth is the same as the multi-carrier OFDM system; however,the PAPR is greatly reduced. In general, as the number of sub-carriersincreases, the PAPR of the OFDM system approaches Gaussian noisestatistics, but regardless of the number of sub-carriers, the SC-FDMPAPR remains substantially the same. Thus, SC-FDM may provide benefitson the uplink by increasing the transmit power efficiency and reducingthe power amplifier cost.

The radio protocol architecture for a radio access network, such as theradio access network 200 shown in FIG. 2, may take on various formsdepending on the particular application. An example for a 4G radioaccess network will now be presented with reference to FIG. 5. FIG. 5 isa conceptual diagram illustrating an example of the radio protocolarchitecture for the user and control planes.

Turning to FIG. 5, the radio protocol architecture for the UE and theeNB is shown with three layers: Layer 1, Layer 2, and Layer 3. Layer 1is the lowest layer and implements various physical layer signalprocessing functions. Layer 1 will be referred to herein as the physicallayer 506. Layer 2 (L2 layer) 508 is above the physical layer 506 and isresponsible for the link between the UE and eNB over the physical layer506.

In the user plane, the L2 layer 508 includes a media access control(MAC) sublayer 510, a radio link control (RLC) sublayer 512, and apacket data convergence protocol (PDCP) 514 sublayer, which areterminated at the eNB on the network side. Although not shown, the UEmay have several upper layers above the L2 layer 508 including a networklayer (e.g., IP layer) that is terminated at the Packet Data Network(PDN) gateway on the network side, and an application layer that isterminated at the other end of the connection (e.g., far end UE, server,etc.).

The PDCP sublayer 514 provides multiplexing between different radiobearers and logical channels. The PDCP sublayer 514 also provides headercompression for upper layer data packets to reduce radio transmissionoverhead, security by ciphering the data packets, and handover supportfor UEs between eNBs. The RLC sublayer 512 provides segmentation andreassembly of upper layer data packets, retransmission of lost datapackets, and reordering of data packets to compensate for out-of-orderreception due to hybrid automatic repeat request (HARQ). The MACsublayer 510 provides multiplexing between logical and transportchannels. The MAC sublayer 510 is also responsible for allocating thevarious radio resources (e.g., resource blocks) in one cell among theUEs. The MAC sublayer 510 is also responsible for HARQ operations. Thephysical sublayer 506 is responsible for transmitting and receiving dataon physical channels (e.g., within time slots of subframes).

In the control plane, the radio protocol architecture for the UE and eNBis substantially the same for the physical layer 506 and the L2 layer508 with the exception that there is no header compression function forthe control plane. The control plane also includes a radio resourcecontrol (RRC) sublayer 516 in Layer 3. The RRC sublayer 516 isresponsible for obtaining radio resources (i.e., radio bearers) and forconfiguring the lower layers using RRC signaling between the eNB and theUE.

In general, packets received by a sublayer from another sublayer may bereferred to as Service Data Units (SDUs), while packets output from asublayer to another sublayer may be referred to as Protocol Data Units(PDUs). For example, packets received by the PDCP sublayer from an upperlayer may be referred to as PDCP SDUs, and packets output from the PDCPsublayer to the RLC sublayer or MAC sublayer may be referred to as PDCPPDUs or RLC/MAC SDUs.

As indicated above, the MAC sublayer 510 may multiplex data frommultiple logical channels (e.g., data from multiple PDCP PDUs), ontotransport channels for transmission within a single MAC PDU. Thus, eachMAC PDU corresponds to one Transport Block (TB) and may include aplurality of multiplexed logical channel MAC SDUs. The physical layer506 may then encode the transport block into a codeword and covert eachcodeword into modulation symbols (e.g., OFDM or SC-FDM symbols) fortransmission to a receiving wireless communication device.

FIG. 6 is a conceptual diagram illustrating the transmission of atransport block 602 within a frame 608 according to some embodiments. Asindicated above, a transport block 602 includes a plurality ofinformation bits passed to the physical layer from the MAC sublayer. Forexample, the MAC sublayer may concatenate one or more MAC SDUs into asingle Transport Block (TB) 602 and append a MAC header 604 to the TB602. The MAC sublayer may further configure the physical sublayer totransmit the TB 602 within a subframe 606 of a frame 608. Additional TBs(not shown) may further be mapped to the same subframe (depending on thenumber of RBs assigned) or other subframes 606 within the frame 608 fortransmission of the additional transport blocks between the base stationand one or more UEs on the downlink or uplink. The transport block 602may be encoded into a codeword and then converted into modulationsymbols (e.g., OFDM symbols or SC-FDM symbols) for transmission in thesubframe 606.

In some examples, each subframe 606 may include a plurality of resourceblocks (RBs), each containing either a suitable number of sub-carriersand OFDM symbols or a single carrier and a suitable number of SC-FDMsymbols. The number of bits carried by each resource element in aresource block depends on the modulation and coding scheme (MCS). Thus,the number of bits included in the TB 602 (e.g., the transport blocksize) depends on the MCS and the number of resource blocks assigned tothe UE. The transport block size (TBS) for each combination of number ofRBs and MCS may be maintained, for example, in a TBS table within thebase station and UE.

For FDD, uplink and downlink frames are separated by frequency andtransmitted continuously and synchronously. For TDD, uplink and downlinksubframes are transmitted on the same frequency and multiplexed in thetime domain. For example, in FIG. 6, the first subframe (subframe #0)may be a downlink subframe, while the next two subframes (e.g., subframe#1 and subframe #2) may be uplink subframes.

In some examples, a UE may be assigned different narrowbands within twoconsecutive uplink subframes (e.g., subframe #1 and subframe #2) in aTDD or FDD system. As used herein, the term narrowband is defined as agroup of six contiguous resource blocks. For example, a UE may beassigned a first narrowband frequency (e.g., a first carrier) within afirst uplink subframe (subframe #1) and a second narrowband frequency(e.g., a second carrier) within a second uplink subframe (subframe #2).

As an example, for Release 13 and Release 14 of LTE, bandwidth-reduced,low-complexity (BL), coverage enhancement (CE) UEs (or BL/CE UEs) maysupport different narrowband frequencies for uplink transmissions. Forexample, a BL/CE UE may transmit a PUCCH or PUSCH within a firstnarrowband in one subframe (e.g., subframe #1) and a PUCCH or PUSCHwithin a second narrowband in the next subframe (e.g., subframe #2). Inthis situation, the BL/CE UE will need to perform frequency retuningfrom the first narrowband to the second narrowband between the twoconsecutive uplink subframes.

To accommodate the frequency retuning process, a guard period istypically created between the two consecutive uplink subframes bypuncturing one or more SC-FDM symbols (e.g., each corresponding to anSC-FDM Sub-Symbol shown in FIG. 4) at the end of the first subframeand/or the beginning of the next subframe. FIG. 7 is a conceptualdiagram illustrating two consecutive uplink subframes 702 a and 702 bimplementing a guard period for frequency retuning between the subframes702 a and 70 b. Each subframe 702 a and 702 b includes a plurality ofSC-FDM symbols (Symbol #1, Symbol #2, . . . , Symbol #N−1, Symbol #N).The guard period may be created by puncturing the last symbol or thelast two symbols (Symbol #N or Symbol #N and Symbol #N−1) in the firstsubframe 702 a and/or puncturing the first symbol or the first twosymbols (Symbol #1 or Symbol #1 and Symbol #2) in the second subframe702 b.

For example, if the BL/CE UE retunes from a first narrowband carryingPUSCH to a second narrowband carrying PUSCH or from a first narrowbandcarrying PUCCH to a second narrowband carrying PUCCH, the guard periodmay be created by puncturing the last SC-FDM symbol (Symbol #N) in thefirst subframe 702 a and the first SC-FDM symbol (Symbol #1) in thesecond subframe 702 b. In addition, if the BL/CE UE retunes from a firstnarrowband carrying PUCCH to a second narrowband carrying PUSCH, theguard period may be created by puncturing the first SC-FDM symbol(Symbol #1) in the second subframe 702 b (e.g., if a shortened PUCCHformat is utilized) or the first two SC-FDM symbols (Symbol #1 andSymbol #2) in the second subframe 702 b (e.g., if a regular PUCCH formatis utilized). Furthermore, if the BL/CE UE retunes from a firstnarrowband carrying PUSCH to a second narrowband carrying PUCCH, theguard period may be created by puncturing the last two SC-FDM symbols(Symbol #N−1 and Symbol #N) in the first subframe 702 a. In each of theabove examples, the punctured PUSCH symbols are counted in the PUSCHmapping, but not used for transmission of the PUSCH.

However, when puncturing PUSCH SC-FDM symbols, decoding errors may occurdepending on the puncturing pattern utilized. For example, the tonescarrying different systematic, parity 1 and parity 2 bits of the turbocode may be lost. As a result, for different numbers of resource blocksand modulation and coding schemes, the log likelihood ratios (LLRs) forsome of the systematic bits at the output of the turbo decoder runningthe BCJR algorithm (MAP algorithm) may converge to zero, even aninfinite signal-to-noise ratio (SNR).

FIG. 8 is a table 800 illustrating examples of combinations ofMCS/number of RBs for which a puncturing pattern of PUSCH symbolshinders decoding at the base station. Each puncturing pattern is for agiven (single) subframe, where the first two bits in the puncturingpattern represent the first PUSCH symbol and the second PUSCH symbol(e.g., Symbol #1 and Symbol #2 shown in FIG. 7) and the last two bits inthe puncturing pattern represent the second to last PUSCH symbol and thelast PUSCH symbol (e.g., Symbol #N−1 and Symbol #N shown in FIG. 7).Thus, in some examples, the puncturing pattern may represent a part of afirst overall puncturing pattern between the given uplink subframe and aprevious subframe and a part of a second overall puncturing patternbetween the given uplink subframe and a subsequent subframe. Asindicated above in reference to FIG. 7, in order to puncture the secondsymbol, the first symbol must also be punctured (e.g., either the firstsymbol or the first and second symbols may be punctured). Similarly, inorder to puncture the second to last symbol, the last symbol must alsobe punctured (e.g., either the last symbol or the last and second tolast symbols may be punctured).

Each combination of MCS index and number of RBs may be referred toherein as a transmission option. As can be seen in FIG. 8, for thetransmission option corresponding to an MCS index of 14 with three RBsbeing assigned to a UE, six out of the eight possible puncturingpatterns are problematic. The only puncturing patterns that do nothinder decoding at the base station are the 0001 puncturing pattern andthe 1000 puncturing pattern. For the transmission option correspondingto an MCS index of 10 with five RBs being assigned to the UE, three ofthe eight possible puncturing patterns are problematic. It should beunderstood that the list of transmission options and puncturing patternsshown in FIG. 8 is merely illustrative, and other transmission optionsand puncturing patterns may also hinder decoding at the base station.

FIG. 8 further illustrates the effective code rate for each transmissionoption and puncturing pattern. Although the effective code rates listedare higher than the code rates without puncturing, decoding at the basestation should still be possible for at least some of the transmissionoptions and number of punctured symbols based on the effective coderates. However, due to the particular puncturing patterns utilized,decoding at the base station may fail.

Therefore, various aspects of the present disclosure provide mechanismsfor mitigating the decoding errors due to symbol puncturing in asubframe of two or more consecutive subframes having the sametransmission direction. In some examples, the symbols that are puncturedare physical uplink shared channel (PUSCH) symbols to provide a guardperiod between consecutive uplink subframes utilizing differentnarrowband frequencies. In other examples, the symbols that arepunctured may be other channel symbols, such as physical downlink sharedchannel (PSDCH) symbols to provide a guard period between consecutivedownlink subframes utilizing different narrowband frequencies.

In some examples, to mitigate the decoding errors, the base station oruser equipment (UE) may select or modify at least one aspect of ascheduling decision involving the communication of a codeword in a givensubframe of at least two consecutive subframes to minimize decodingerrors. For example, a selected puncturing pattern or a transport blocksize associated with a selected transmission option may be modified.

In some examples, the base station may avoid selecting any of thetransmission options and associated puncturing patterns that may hinderdecoding at the receiver when making the scheduling decision forcommunication of the codeword in the given subframe. In other examples,the base station may take into account an impact on subframe N−1 whenmaking a scheduling decision on subframe N. For example, the basestation may modify a narrowband scheduled for subframe N to match thenarrowband scheduled for subframe N−1 to prevent puncturing of thesymbols in subframe N−1 and/or subframe N. As another example, the basestation may simply cancel scheduling of a codeword in subframe N for theUE.

In some examples, the UE or base station may modify the puncturingpattern to puncture different symbols or fewer symbols within the twoconsecutive subframes. In other examples, the UE or base station maymodify the transport block size as a function of the selectedtransmission option and puncturing pattern. For example, a transportblock size table maintained at the UE or base station may be modifiedfor the problematic transmission options (e.g., number of resourceblocks and MCS that may produce decoding errors based on the puncturingpattern).

In other aspects of the disclosure, the base station or UE may utilize aturbo decoder to try different combinations of the punctured bits thatresult in a cyclic redundancy code (CRC) pass to attempt to decode thepunctured subframe(s). The base station or UE may further run a Viterbialgorithm, possibly also utilizing the tail bits in the trellistermination of the turbo code to obtain the punctured bits that resultin a CRC pass.

FIG. 9 is a block diagram illustrating an example of a hardwareimplementation for a scheduling entity 900 employing a processing system914. For example, the scheduling entity 900 may be a base station asillustrated in any one or more of FIGS. 1 and/or 2. In another example,the scheduling entity 900 may be a user equipment (UE) as illustrated inany one or more of FIGS. 1 and 2.

The scheduling entity 900 may be implemented with a processing system914 that includes one or more processors 904. Examples of processors 904include microprocessors, microcontrollers, digital signal processors(DSPs), field programmable gate arrays (FPGAs), programmable logicdevices (PLDs), state machines, gated logic, discrete hardware circuits,and other suitable hardware configured to perform the variousfunctionality described throughout this disclosure. In various examples,the scheduling entity 900 may be configured to perform any one or moreof the functions described herein. That is, the processor 904, asutilized in a scheduling entity 900, may be used to implement any one ormore of the processes and procedures described below. The processor 904may in some instances be implemented via a baseband or modem chip and inother implementations, the processor 904 may itself comprise a number ofdevices distinct and different from a baseband or modem chip (e.g., insuch scenarios is may work in concert to achieve embodiments discussedherein). And as mentioned above, various hardware arrangements andcomponents outside of a baseband modem processor can be used inimplementations, including RF-chains, power amplifiers, modulators,buffers, interleavers, adders/summers, etc.

In this example, the processing system 914 may be implemented with a busarchitecture, represented generally by the bus 902. The bus 902 mayinclude any number of interconnecting buses and bridges depending on thespecific application of the processing system 914 and the overall designconstraints. The bus 902 communicatively couples together variouscircuits including one or more processors (represented generally by theprocessor 904), a memory 905, and computer-readable media (representedgenerally by the computer-readable medium 906). The bus 902 may alsolink various other circuits such as timing sources, peripherals, voltageregulators, and power management circuits, which are well known in theart, and therefore, will not be described any further. A bus interface908 provides an interface between the bus 902 and a transceiver 910. Thetransceiver 910 provides a communication interface or means forcommunicating with various other apparatus over a transmission medium.Depending upon the nature of the apparatus, a user interface 912 (e.g.,keypad, display, speaker, microphone, joystick) may also be provided. Ofcourse, such a user interface 912 is optional, and may be omitted insome examples, such as a base station.

The processor 904 is responsible for managing the bus 902 and generalprocessing, including the execution of software stored on thecomputer-readable medium 906. The software, when executed by theprocessor 904, causes the processing system 914 to perform the variousfunctions described below for any particular apparatus. Thecomputer-readable medium 906 and the memory 905 may also be used forstoring data that is manipulated by the processor 904 when executingsoftware.

One or more processors 904 in the processing system may executesoftware. Software shall be construed broadly to mean instructions,instruction sets, code, code segments, program code, programs,subprograms, software modules, applications, software applications,software packages, routines, subroutines, objects, executables, threadsof execution, procedures, functions, etc., whether referred to assoftware, firmware, middleware, microcode, hardware descriptionlanguage, or otherwise. The software may reside on a computer-readablemedium 906.

The computer-readable medium 906 may be a non-transitorycomputer-readable medium. A non-transitory computer-readable mediumincludes, by way of example, a magnetic storage device (e.g., hard disk,floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD)or a digital versatile disc (DVD)), a smart card, a flash memory device(e.g., a card, a stick, or a key drive), a random access memory (RAM), aread only memory (ROM), a programmable ROM (PROM), an erasable PROM(EPROM), an electrically erasable PROM (EEPROM), a register, a removabledisk, and any other suitable medium for storing software and/orinstructions that may be accessed and read by a computer. Thecomputer-readable medium may also include, by way of example, a carrierwave, a transmission line, and any other suitable medium fortransmitting software and/or instructions that may be accessed and readby a computer. The computer-readable medium 906 may reside in theprocessing system 914, external to the processing system 914, ordistributed across multiple entities including the processing system914. The computer-readable medium 906 may be embodied in a computerprogram product. By way of example, a computer program product mayinclude a computer-readable medium in packaging materials. Those skilledin the art will recognize how best to implement the describedfunctionality presented throughout this disclosure depending on theparticular application and the overall design constraints imposed on theoverall system.

In some aspects of the disclosure, the processor 904 may includecircuitry configured for various functions. For example, the processor904 may include resource assignment and scheduling circuitry 941,configured to generate, schedule, and modify a resource assignment orgrant of time-frequency resources (e.g., a set of one or more resourceelements). For example, the resource assignment and scheduling circuitry941 may schedule time-frequency resources within a plurality of timedivision duplex (TDD) and/or frequency division duplex (FDD) subframesto carry traffic and/or control information to and/or from multiple UEs(scheduled entities).

In accordance with various aspects of the present disclosure, theresource assignment and scheduling circuitry 941 may access atransmission option (TO) table 915 maintained, for example, in memory905 to schedule uplink or downlink transmissions for a scheduled entity(UE). The transmission option table 915 may include a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS) index. Inaddition, each of the transmission options in the table 915 may beassociated with one or more puncturing patterns, some of which mayhinder decoding at the receiver. An example of a portion of atransmission option table 915 may include the table 800 shown in FIG. 8for PUSCH.

The resource assignment and scheduling circuitry 941 may make ascheduling decision for at least two consecutive subframes, each havingthe same transmission direction, based on the table 915. In someexamples, the scheduling decision includes at least a selectedtransmission option from the table 915 for communication of a codewordbetween the scheduling entity and a scheduled entity (UE) in a givensubframe of the at least two consecutive subframes. In particular, theresource assignment and scheduling circuitry 941 may select at least oneaspect of the scheduling decision for communication of the codeword inthe given subframe to reduce decoding errors of the codeword at thereceiver. For example, the at least one aspect may include one or moreof a transmission option, a puncturing pattern, transport block size, ordecoder/decoding algorithm for the codeword and/or scheduling of anothercodeword within the at least two consecutive subframes.

The below description is provided for an uplink subframe carrying aPUSCH. However, it should be understood that the description may beequally applied to a downlink subframe carrying a PDSCH or othersymbols.

In some examples, when scheduling a given (current) uplink subframe fortransmitting a PUSCH for a particular UE, the resource assignment andscheduling circuitry 941 may utilize the table 915 to avoid schedulingany of the transmission options and associated puncturing patterns thatmay hinder decoding at the receiver listed in the table 915. Forexample, the resource assignment and scheduling circuitry 941 maydetermine whether the UE will need to puncture the current uplinksubframe to create a guard period between the current uplink subframeand an immediately preceding uplink subframe as a result of differentnarrowbands being assigned to the UE in the current uplink subframe andthe immediately preceding uplink subframe. If a guard period isnecessary, the resource assignment and scheduling circuitry 941 mayavoid scheduling any of the combinations of MCS index, number ofresource blocks, and problematic puncturing patterns listed in the table915 for the PUSCH for the particular UE in the current subframe. In someexamples, the resource assignment and scheduling circuitry 941 maysimply avoid scheduling any transmission options that have problematicpuncturing patterns listed in the table 915. The resource assignment andscheduling circuitry 941 may then either select a transmission optionand associated puncturing pattern from the table 915 that enablesdecoding at the receiver or schedule the PUSCH for the UE within a lateruplink subframe if there are no other transmission options andassociated puncturing patterns that are not problematic available forthe current subframe.

In other examples, the resource assignment and scheduling circuitry 941may modify the selected problematic puncturing pattern to puncturedifferent symbols in the current uplink subframe and the immediatelypreceding/subsequent subframe or to puncture fewer symbols in thecurrent uplink subframe and the immediate preceding/subsequent subframe.The modified puncturing pattern may be included within the downlinkcontrol information (DCI) carrying the uplink grant for the codeword.

In still other examples, after scheduling a first uplink subframe forthe UE to transmit a PUSCH, the resource assignment and schedulingcircuitry 941 may modify at least one aspect of the scheduling decisionrelated to a second consecutive uplink subframe for the UE based on thetable 915. For example, the resource assignment and scheduling circuitry941 may utilize the table 915 to determine whether the UE will need topuncture the first uplink subframe to create a guard period between thefirst uplink subframe and the second uplink subframe that will result inone of the problematic puncturing patterns for the transmission optionselected for the first uplink subframe listed in the table 915. If theUE will need to puncture the first subframe utilizing one of theproblematic puncturing patterns listed for the transmission optionalready selected by the resource assignment and scheduling circuitry 941for the first uplink subframe, the resource assignment and schedulingcircuitry 941 may modify the scheduling decision for the second uplinksubframe to prevent the UE from puncturing the first uplink subframe tocreate the guard period.

In some examples, the resource assignment and scheduling circuitry 941may modify the narrowband assigned to the second uplink subframe tomatch that of the first uplink subframe so that the UE does not need tocreate the guard period, thereby preventing the problematic puncturingpattern in the first uplink subframe. In other examples, the resourceassignment and scheduling circuitry 941 may cancel scheduling of aplanned uplink transmission in the second uplink subframe for the UE.For example, the resource assignment and scheduling circuitry 941 mayre-schedule uplink transmission originally planned for the second uplinksubframe to another subsequent subframe that is not contiguous with thefirst uplink subframe.

By canceling scheduling of the planned uplink transmission in the seconduplink subframe for the UE, the UE may not need to create the guardperiod or may not need to utilize the particular problematic puncturingpattern, depending on any re-scheduling of the second uplink subframe.For example, if the resource assignment and scheduling circuitry 941does not schedule any uplink transmissions within the second uplinksubframe, the UE will not need to create the guard period between thefirst and second uplink subframes. As another example, if the resourceassignment and scheduling circuitry 941 re-schedules the second uplinksubframe to utilize the same narrowband as the first uplink subframe(e.g., as a result of scheduling different uplink information in thesecond uplink subframe), the UE will not need to create the guard periodbetween the first and second uplink subframes. As yet another example,if the resource assignment and scheduling circuitry 941 re-schedules thesecond uplink subframe to include a different narrowband than the firstuplink subframe, but different uplink information (e.g., a PUCCH insteadof a PUSCH or a PUSCH instead of a PUCCH), the resulting puncturingpattern required for the first subframe may not be problematic. Theresource assignment and scheduling circuitry 941 may further operate incoordination with resource assignment and scheduling software 951.

The processor 904 may further include downlink (DL) traffic and controlchannel generation and transmission circuitry 942, configured togenerate and transmit downlink traffic and control signals/channels. Forexample, the DL traffic and control channel generation and transmissioncircuitry 942 may be configured to generate a physical downlink controlchannel (PDCCH) including downlink control information (DCI) and/or aphysical downlink shared channel (PDSCH) including downlink traffic. Inaddition, the DL traffic and control channel generation and transmissioncircuitry 942 may operate in coordination with the resource assignmentand scheduling circuitry 941 to schedule the DL traffic and/or controlinformation and to place the DL traffic and/or control information ontoa time division duplex (TDD) or frequency division duplex (FDD) carrierwithin one or more subframes or time slots in accordance with theresources assigned to the DL traffic and/or control information. The DLtraffic and control channel generation and transmission circuitry 942may further be configured to multiplex DL transmissions utilizing timedivision multiplexing (TDM), code division multiplexing (CDM), frequencydivision multiplexing (FDM), orthogonal frequency division multiplexing(OFDM), sparse code multiplexing (SCM), or other suitable multiplexingschemes.

In accordance with various aspects of the disclosure, the DL traffic andcontrol channel generation and transmission circuitry 942 may beconfigured to access the TO table 915 to generate and transmit adownlink transmission, such as a PDSCH, to a UE. In some examples, whengenerating a PDSCH transmission for a given downlink subframe, the DLtraffic and control channel generation and transmission circuitry 942may operate in coordination with the resource assignment and schedulingcircuitry 941 to modify a transport block size for the PDSCHtransmission based on the table 915. For example, the DL traffic andcontrol channel generation and transmission circuitry 942 may determinewhether the PDSCH needs to be punctured at the UE for the given downlinksubframe, and if so, whether, based on the assigned transmission optionfor the given downlink subframe (e.g., the MCS and number of resourceblocks allocated for the PDSCH transmission in the given downlinksubframe), the particular puncturing pattern may result in one of theproblematic puncturing patterns for the assigned transmission optionbased on the table 915.

In some examples, to mitigate the decoding errors, the transport block(TB) size for a selected transmission option listed in the transmissionoption table 915 may be modified. The TB size is determined based on theselected MCS and number of resource blocks allocated to the scheduledentity, as obtained from a TBS table 916 maintained, for example, inmemory 905. For example, upon determining the MCS index and number ofresource blocks assigned to the PDSCH transmission, the DL traffic andcontrol channel generation and transmission circuitry 942 and/orresource assignment and scheduling circuitry 941 may access the TBStable 916 to look-up the TB size corresponding to the MCS index andnumber of RBs. The TB size table 916 may be modified to includedifferent TB sizes for the problematic transmission options asillustrated in FIG. 8 (e.g., the combinations of MCS index and number ofresource blocks included within the transmission option table 915). Insome examples, the transport block size may also be modified based onthe associated puncturing patterns. For example, the TB size table 916may include multiple entries for the problematic transmission options,with different TB sizes being utilized for different puncturingpatterns.

In some examples, the DL traffic and control channel generation andtransmission circuitry 942 may further generate and transmit one or morePDCCH, each containing DCI indicating the scheduling decision (e.g., adownlink assignment or uplink grant) for at least one of the two or moreconsecutive subframes. For example, the DCI may indicate the selectedtransmission option, selected puncturing pattern or modified puncturingpattern (if applicable), and selected transport block size (ifapplicable). The DL traffic and control channel generation andtransmission circuitry 942 may further operate in coordination with DLdata and control channel generation and transmission software 952.

The processor 904 may further include uplink (UL) traffic and controlchannel reception and processing circuitry 943, configured to receiveand process uplink control channels and uplink traffic channels from oneor more scheduled entities. For example, the UL traffic and controlchannel reception and processing circuitry 943 may be configured toreceive uplink traffic (e.g., a PUSCH) from one or more scheduledentities. The UL traffic and control channel reception and processingcircuitry 943 may further be configured to receive a Physical UplinkControl Channel (PUCCH). The UL traffic and control channel receptionand processing circuitry 943 may further operate in coordination with ULtraffic and control channel reception and processing software 953.

The processor 904 may further include a decoder 944, configured toreceive and decode an uplink codeword produced from an uplinktransmission including one or more punctured PUSCH symbols in an uplinksubframe. In some examples, the decoder 944 may be a turbo decoderrunning a BCJR algorithm (MAP algorithm). In some examples, if the PUSCHsymbols punctured from the uplink subframe result in systematic bits(information bits within the PUSCH symbols) for which the LLRs convergeto zero, the turbo decoder 944 may run a Viterbi algorithm with the LLRsof the systematic and parity 1/parity 2 bits for one or both of theconvolutional decoders of the turbo decoder 944. The tail bits in thetrellis termination of the turbo code may then be utilized to obtain themessage bits (information bits) that will result in the correcttermination. In other examples, the turbo decoder 944 may try differentcombinations of the punctured bits that result in a cyclic redundancycode (CRC) pass to attempt to decode the codeword containing thepunctured subframe(s). The decoder 944 may further operate incoordination with decoding software 954.

FIG. 10 is a conceptual diagram illustrating an example of a hardwareimplementation for an exemplary scheduled entity 1000 employing aprocessing system 1014. In accordance with various aspects of thedisclosure, an element, or any portion of an element, or any combinationof elements may be implemented with a processing system 1014 thatincludes one or more processors 1004. For example, the scheduled entity1000 may be a user equipment (UE) as illustrated in any one or more ofFIGS. 1 and/or 2. In various aspects of the present disclosure, thescheduled entity may be a BL/CE UE implementing eMTC, as described inRelease 13 and/or Release 14 of LTE.

The processing system 1014 may be substantially the same as theprocessing system 914 illustrated in FIG. 9, including a bus interface1008, a bus 1002, memory 1005, a processor 1004, and a computer-readablemedium 1006. Furthermore, the scheduled entity 1000 may include a userinterface 1012 and a transceiver 1010 substantially similar to thosedescribed above in FIG. 9. That is, the processor 1004, as utilized in ascheduled entity 1000, may be used to implement any one or more of theprocesses described below.

In some aspects of the disclosure, the processor 1004 may include uplink(UL) traffic and control channel generation and transmission circuitry1042, configured to generate and transmit uplinkcontrol/feedback/acknowledgement information on an UL control channel.For example, the UL traffic and control channel generation andtransmission circuitry 1042 may be configured to generate and transmitan uplink control channel (e.g., a Physical Uplink Control Channel(PUCCH)) containing uplink control information (UCI). In addition, theUL traffic and control channel generation and transmission circuitry1042 may be configured to generate and transmit uplink traffic on an ULtraffic channel (e.g., a PUSCH) in accordance with an uplink grant.

In accordance with various aspects of the disclosure, the UL traffic andcontrol channel generation and transmission circuitry 1042 may beconfigured to access a transmission option table 1015 maintained, forexample, in memory 1005 to generate and transmit an uplink transmissionto the base station. The transmission option table 1015 may include aplurality of transmission options, each including a respective number ofresource blocks and a respective modulation and coding scheme (MCS)index. In addition, each of the transmission options in the table 1015may be associated with one or more puncturing patterns, some of whichmay hinder decoding at the base station. An example of a portion of atransmission option table 1015 may include the table 800 shown in FIG.8. In addition, the transmission option table 1015 may correspond to thetransmission option table 915 shown in FIG. 9.

In some examples, when generating a PUSCH transmission for a given(current) uplink subframe, the UL traffic and control channel generationand transmission circuitry 1042 may utilize the table 1015 to modify atleast one aspect (e.g., the puncturing pattern or a transport blocksize) of a scheduling decision for the PUSCH transmission based on thetable 1015. For example, the UL traffic and control channel generationand transmission circuitry 1042 may determine whether the PUSCH needs tobe punctured for the current uplink subframe to create a guard periodbetween the current uplink subframe and an immediately preceding uplinksubframe and/or an immediately subsequent subframe as a result ofdifferent narrowbands being assigned to the scheduled entity 1000 in thecurrent uplink subframe and the immediately preceding/subsequent uplinksubframe. If a guard period is necessary, the UL traffic and controlchannel generation and transmission circuitry 1042 may determinewhether, based on the assigned transmission option for the currentuplink subframe (e.g., the MCS and number of resource blocks allocatedto the UE for the current uplink subframe), the particular puncturingpattern typically utilized to create the guard period between thecurrent uplink subframe and the immediately preceding/subsequentsubframe may result in one of the problematic puncturing patterns forthe assigned transmission option based on the table 1015.

For example, if the immediately preceding subframe includes a PUCCHtransmitted within a first narrowband and the current uplink subframeincludes a PUSCH transmitted within a second, different narrowband, thepuncturing pattern for the current uplink subframe includes the firsttwo PUSCH symbols, assuming a regular PUCCH format was utilized. Lookingat the table in FIG. 8, if the assigned transmission option for thecurrent uplink subframe includes the combination of an MCS index of tenand five resource blocks, the puncturing pattern for the current uplinksubframe may result in decoding errors at the base station.

In some examples, to mitigate the decoding errors, the UL traffic andcontrol channel generation and transmission circuitry 1042 may modifythe puncturing pattern and operate in coordination with puncturingcircuitry 1044 to puncture different symbols in the current uplinksubframe and the immediately preceding/subsequent subframe or topuncture fewer symbols in the current uplink subframe and the immediatepreceding/subsequent subframe. Using the above example from FIG. 8, theUL traffic and control channel generation and transmission circuitry1042 may modify the puncturing pattern to cause the puncturing circuitry1044 to puncture the last symbol of the immediately preceding subframecontaining the PUCCH and only the first symbol of the current uplinksubframe containing the PUSCH. As another example, if there is acontinuous PUSCH transmission over three or more consecutive uplinksubframes with narrowband hopping between each of the uplink subframes,the normal (conventional) puncturing pattern requires puncturing thefirst and last PUSCH symbols in each subframe. If puncturing the firsttwo symbols or the last two symbols of the current uplink subframeresults in reduced decoding errors (e.g., fewer numbers of bitsconverging to zero) at the base station, the UL traffic and controlchannel generation and transmission circuitry 1042 may cause thepuncturing circuitry 1044 to puncture the first two or the last twoPUSCH symbols in the current uplink subframe instead of the first andlast PUSCH symbol.

As yet another example, if the scheduled entity 1000 is able to retunefrom one narrowband to another narrowband faster (e.g., within theduration of one symbol instead of two symbols), the UL traffic andcontrol channel generation and transmission circuitry 1042 may modifythe puncturing pattern to cause the puncturing circuitry 1044 topuncture fewer PUSCH symbols between the two consecutive uplinksubframes to avoid the problematic puncturing patterns for each of theconsecutive uplink subframes. In this example, the base station maydetect the signal from the scheduled entity (UE) on the symbols that arenot punctured and attempt decoding based on the detected signal.

In other examples, to mitigate the decoding errors, the transport block(TB) size for the transmission options listed in the transmission optiontable 1015 may be modified. The TB size is determined based on theselected MCS and number of resource blocks allocated to the scheduledentity, as obtained from a TB size table 1016 maintained, for example,in memory 1005. For example, upon determining the MCS index and numberof resource blocks assigned to the scheduled entity for a particularuplink transmission, the UL traffic and control channel generation andtransmission circuitry 1042 may access the TB size table 1016 to look-upthe TB size corresponding to the MCS index and number of RBs. The TBsize table 1016 may be modified to include different TB sizes for theproblematic transmission options as illustrated in FIG. 8 (e.g., thecombinations of MCS index and number of resource blocks included withinthe transmission option table 1015).

In some examples, the transport block size may also be modified based onthe associated puncturing patterns. For example, the TB size table 1016may include multiple entries for the problematic transmission options,with different TB sizes being utilized for different puncturingpatterns. For example, for the problematic case of MCS index equal tofourteen with three RBs assigned to a UE, the modified TB size may beutilized for only the six problematic puncturing patterns shown in FIG.8. The UL traffic and control channel generation and transmissioncircuitry 1042 may operate in coordination with UL traffic and controlchannel generation and transmission software 1052. In addition, thepuncturing circuitry 1044 may operate in coordination with puncturingsoftware 1054.

The processor 1004 may further include downlink (DL) traffic and controlchannel reception and processing circuitry 1046, configured forreceiving and processing downlink traffic on a traffic channel (e.g.,PDSCH), and to receive and process control information (e.g., a downlinkassignment or uplink grant) on one or more downlink control channels. Insome examples, received downlink traffic and/or control information maybe temporarily stored in a data buffer 1018 within memory 1005.

In various aspects of the disclosure, the DL traffic and control channelreception and processing circuitry 1046 may further be configured topuncture a received PDSCH in a given (current) downlink subframe toenable the scheduled entity 1000 to retune from one narrowband (e.g.,the narrowband utilized for the given downlink subframe or a previousdownlink subframe) to another narrowband (e.g., the narrowband utilizedfor the given downlink subframe or a subsequent downlink subframe). Tomitigate the decoding errors, the DL traffic and control channelreception and processing circuitry 1046 may modify the puncturingpattern, based on the TO table 1015, to puncture different symbols inthe current downlink subframe or to puncture fewer symbols in thecurrent downlink subframe. The DL traffic and control channel receptionand processing circuitry 1046 may operate in coordination with DLtraffic and control channel reception and processing software 1056.

The processor 1004 may further include a decoder 1048, configured toreceive and decode a downlink codeword produced from a downlinktransmission including one or more punctured PDSCH symbols (punctured atthe scheduled entity 1000) in a downlink subframe. In some examples, thedecoder 1048 may be a turbo decoder running a BCJR algorithm (MAPalgorithm). In some examples, if the PDSCH symbols punctured from thedownlink subframe result in systematic bits (information bits within thePDSCH symbols) for which the LLRs converge to zero, the turbo decoder1048 may run a Viterbi algorithm with the LLRs of the systematic andparity 1/parity 2 bits for one or both of the convolutional decoders ofthe turbo decoder 1048. The tail bits in the trellis termination of theturbo code may then be utilized to obtain the message bits (informationbits) that will result in the correct termination. In other examples,the turbo decoder 1048 may try different combinations of the puncturedbits that result in a cyclic redundancy code (CRC) pass to attempt todecode the codeword containing the punctured subframe(s). The decoder1048 may further operate in coordination with decoding software 1058.

FIG. 11 is a table illustrating examples of combinations of MCS indexand number of RBs for which a modified transport block size for PUSCHreduces the decoding errors at the receiver, in accordance with aspectsof the present disclosure. FIG. 11 includes the same combinations of MCSindex and number of RBs (transmission options) as in FIG. 8 for which aparticular puncturing pattern hinders decoding at the receiver. FIG. 11further includes a modified transport block size for which the decodingerrors at the receiver are not observed. For example, for eachtransmission option utilizing an MCS index of fourteen and three RBs, ifthe transport block size is increased from 744 bits to 760 bits, thedecoding errors at the receiver are mitigated. Similarly, for eachtransmission option utilizing an MCS index of ten with five RBs, if thetransport block size is decreased from 872 bits to 856 bits, thedecoding errors at the receiver are mitigated.

FIG. 11 further illustrates the modified effective code rate for eachtransmission option and puncturing pattern when the TB size is modifiedas shown in FIG. 11. As can be seen in FIG. 11, the modified code ratefor the modified TB size for each of the transmission options isslightly shifted with respect to the original effective code rate forthe original TB size.

FIG. 12 is a flow chart illustrating an exemplary process 1200 for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the present disclosure. As described below,some or all illustrated features may be omitted in a particularimplementation within the scope of the present disclosure, and someillustrated features may not be required for implementation of allembodiments. In some examples, the process 1200 may be carried out bythe scheduling entity 900 illustrated in FIG. 9. In some examples, theprocess 1200 may be carried out by any suitable apparatus or means forcarrying out the functions or algorithm described below.

At block 1202, the scheduling entity may identify a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS). At block1204, the scheduling entity may identify respective puncturing patternsfor each of the transmission options for at least two consecutivesubframes, each having a same transmission direction. In some examples,the puncturing patterns enable retuning of a user equipment (UE) from afirst narrowband utilized by the UE in a first subframe to a secondnarrowband utilized by the UE in a second subframe. In some examples,one or more of the puncturing patterns associated with one or more ofthe transmission options may hinder decoding of a codeword communicatedbetween the scheduling entity and the UE within a given subframe of theat least two consecutive subframes. For example, the resource assignmentand scheduling circuitry 941 shown and described above in reference toFIG. 9 may access a transmission option table 915 to identify theplurality of transmission options and associated puncturing patterns.

At block 1206, the scheduling entity may make a scheduling decision forthe at least two consecutive subframes based on the transmission optionsand associated puncturing patterns. In some examples, the schedulingentity may make the scheduling decision by selecting at least one aspectof the scheduling decision to reduce decoding errors of the codewordcommunicated in the given subframe. In some examples, the at least twoconsecutive subframes may include uplink subframes and the codeword maybe communicated over physical uplink shared channel (PUSCH) SC-FDMAsymbols. In other examples, the at least two consecutive subframes mayinclude downlink subframes and the codeword may be communicated overphysical downlink shared channel (PDSCH) SC-FDMA symbols.

In some examples, the scheduling entity may make the scheduling decisionby avoiding scheduling any of the transmission options that haveproblematic puncturing patterns or avoiding scheduling the problematicpuncturing patterns for any of the transmission options for the at leasttwo consecutive subframes for a UE. In other examples, the schedulingentity may make the scheduling decision by modifying a narrowbandscheduled for a second one of the at least two consecutive subframes tomatch a first one of the at least two consecutive subframes. In stillother examples, the scheduling entity may cancel scheduling of a secondcodeword for communication between the scheduling entity and the UE inthe second subframe to avoid puncturing the codeword communicated in thefirst subframe. Other aspects of the scheduling decision may further beselected to reduce decoding errors of the codeword at the receiver. Forexample, the resource assignment and scheduling circuitry 941 shown anddescribed above in reference to FIG. 9 may make the scheduling decisionfor the at least two consecutive subframes.

FIG. 13 is a flow chart illustrating an exemplary process 1300 for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the present disclosure. As described below,some or all illustrated features may be omitted in a particularimplementation within the scope of the present disclosure, and someillustrated features may not be required for implementation of allembodiments. In some examples, the process 1300 may be carried out bythe scheduling entity 900 illustrated in FIG. 9. In some examples, theprocess 1300 may be carried out by any suitable apparatus or means forcarrying out the functions or algorithm described below.

At block 1302, the scheduling entity may identify a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS). At block1304, the scheduling entity may identify respective puncturing patternsfor each of the transmission options for at least two consecutivesubframes, each having a same transmission direction. In some examples,the puncturing patterns enable retuning of a user equipment (UE) from afirst narrowband utilized by the UE in a first subframe to a secondnarrowband utilized by the UE in a second subframe. In some examples,one or more of the puncturing patterns associated with one or more ofthe transmission options may hinder decoding of a codeword communicatedbetween the scheduling entity and the UE within a given subframe of theat least two consecutive subframes. For example, the resource assignmentand scheduling circuitry 941 shown and described above in reference toFIG. 9 may access a transmission option table 915 to identify theplurality of transmission options and associated puncturing patterns.

At block 1306, the scheduling entity may select a selected transmissionoption from the plurality of transmission options for communication of acodeword between the scheduling entity and the UE in a given subframe ofthe at least two consecutive subframes. In some examples, the at leasttwo consecutive subframes may include uplink subframes and the codewordmay be communicated over physical uplink shared channel (PUSCH) SC-FDMAsymbols. In other examples, the at least two consecutive subframes mayinclude downlink subframes and the codeword may be communicated overphysical downlink shared channel (PDSCH) SC-FDMA symbols. For example,the resource assignment and scheduling circuitry 941 shown and describedabove in reference to FIG. 9 may select the selected transmissionoption.

At block 1308, the scheduling entity may identify problematic puncturingpatterns for the selected transmission option for the given subframethat may hinder decoding of the codeword at the receiver. For example,the resource assignment and scheduling circuitry 941 shown and describedabove in reference to FIG. 9 may identify the problematic puncturingpattern(s) associated with the selected transmission option

At block 1310, the scheduling entity may determine whether a selectedpuncturing pattern (PP) for the transmission option is problematic. Ifthe selected puncturing pattern is not problematic (N branch of block1310), at block 1312, the scheduling entity may utilize the selectedpuncturing pattern for communication of the codeword to enable decodingof the codeword at the receiver and allow the UE to retune narrowbandsbetween the given subframe and an immediately consecutive (prior orsubsequent) subframe. For example, the resource assignment andscheduling circuitry 941 shown and described above in reference to FIG.9 may utilize the selected puncturing pattern for schedulingcommunication of the codeword in the given subframe.

If the selected puncturing pattern is problematic (Y branch of block1310), the process proceeds to either block 1314 or block 1316. At block1314, the scheduling entity may modify the selected puncturing patternto puncture different symbols in the given subframe and the immediatelypreceding/subsequent subframe or to puncture fewer symbols in the givensubframe and the immediate preceding/subsequent subframe. The modifiedpuncturing pattern may be included within the downlink controlinformation (DCI) carrying the downlink assignment or uplink grant forthe codeword. For example, the resource assignment and schedulingcircuitry 941 shown and described above in reference to FIG. 9 maymodify the puncturing pattern.

At block 1316, the scheduling entity may modify a transport block sizeof the codeword. For example, upon determining the transport block sizecorresponding to the selected transmission option, the scheduling entitymay access a table to identify a modified transport block size that maybe utilized for the selected transmission option. In some examples, thetransport block size may also be modified based on the associatedpuncturing patterns. For example, the DL traffic and control channelgeneration and transmission circuitry 942 and the resource assignmentand scheduling circuitry 941 shown and described above in reference toFIG. 9 may modify the transport block size of the codeword.

FIG. 14 is a flow chart illustrating an exemplary process 1400 for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the present disclosure. As described below,some or all illustrated features may be omitted in a particularimplementation within the scope of the present disclosure, and someillustrated features may not be required for implementation of allembodiments. In some examples, the process 1400 may be carried out bythe scheduling entity 900 illustrated in FIG. 9. In some examples, theprocess 1400 may be carried out by any suitable apparatus or means forcarrying out the functions or algorithm described below.

At block 1402, the scheduling entity may identify a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS). At block1404, the scheduling entity may identify respective puncturing patternsfor each of the transmission options for at least two consecutivesubframes, each having a same transmission direction. In some examples,the puncturing patterns enable retuning of a user equipment (UE) from afirst narrowband utilized by the UE in a first subframe to a secondnarrowband utilized by the UE in a second subframe. In some examples,one or more of the puncturing patterns associated with one or more ofthe transmission options may hinder decoding of a codeword communicatedbetween the scheduling entity and the UE within a given subframe of theat least two consecutive subframes. For example, the resource assignmentand scheduling circuitry 941 shown and described above in reference toFIG. 9 may access a transmission option table 915 to identify theplurality of transmission options and associated puncturing patterns.

At block 1406, the scheduling entity may select respective selectedtransmission options from the plurality of transmission options forcommunication between the scheduling entity and the UE for a firstsubframe and a second subframe of the at least two consecutivesubframes, where the first and second subframes are consecutive. In someexamples, the first and second subframes may include uplink subframesand the codeword may be communicated over physical uplink shared channel(PUSCH) SC-FDMA symbols. In other examples, the first and secondsubframes may include downlink subframes and the codeword may becommunicated over physical downlink shared channel (PDSCH) SC-FDMAsymbols. For example, the resource assignment and scheduling circuitry941 shown and described above in reference to FIG. 9 may select theselected transmission option.

At block 1408, the scheduling entity may determine that a guard periodmay need to be created by the UE between the first and second subframes,and may therefore, select a puncturing pattern associated with theselected transmission option for at least the first subframe forcommunication of a first codeword between the scheduling entity and theUE in the first subframe. For example, the resource assignment andscheduling circuitry 941 shown and described above in reference to FIG.9 may select a puncturing pattern associated with the selectedtransmission option.

At block 1410, the scheduling entity may identify the narrowbandsscheduled for the UE for the first subframe and the second subframe. Forexample, the resource assignment and scheduling circuitry 941 shown anddescribed above in reference to FIG. 9 may identify the narrowbands fromthe selected transmission options.

At block 1412, the scheduling entity may determine whether the selectedpuncturing pattern (PP) for the selected transmission option for thefirst subframe is problematic. If the selected puncturing pattern isproblematic (Y branch of block 1412), the process proceeds to eitherblock 1414, block 1416, or block 1418. At block 1414, the schedulingentity may modify the second narrowband in the second subframe to matchthe first narrowband in the first subframe to avoid puncturing of thefirst codeword. For example, the resource assignment and schedulingcircuitry 941 shown and described above in reference to FIG. 9 maymodify the narrowband.

At block 1416, the scheduling entity may cancel scheduling of a secondcodeword in the second subframe to avoid puncturing of the firstcodeword in the first subframe. For example, the resource assignment andscheduling circuitry 941 shown and described above in reference to FIG.9 may cancel scheduling of the second codeword.

At block 1418, the scheduling entity may modify a type of information(e.g., PUCCH or PUSCH) communicated in the second subframe to modify thepuncturing pattern utilized in the first subframe. For example, theresource assignment and scheduling circuitry 941 may modify the type ofinformation communicated in the second subframe.

FIG. 15 is a flow chart illustrating an exemplary process 1500 for ascheduling entity to mitigate decoding errors due to puncturing, inaccordance with aspects of the present disclosure. As described below,some or all illustrated features may be omitted in a particularimplementation within the scope of the present disclosure, and someillustrated features may not be required for implementation of allembodiments. In some examples, the process 1500 may be carried out bythe scheduling entity 900 illustrated in FIG. 9. In some examples, theprocess 1500 may be carried out by any suitable apparatus or means forcarrying out the functions or algorithm described below.

At block 1502, the scheduling entity may identify a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS). At block1504, the scheduling entity may identify respective puncturing patternsfor each of the transmission options for at least two consecutive uplinksubframes. In some examples, the puncturing patterns enable retuning ofa user equipment (UE) from a first narrowband utilized by the UE in afirst subframe to a second narrowband utilized by the UE in a secondsubframe. In some examples, one or more of the puncturing patternsassociated with one or more of the transmission options may hinderdecoding of a codeword communicated within a given subframe of the atleast two consecutive uplink subframes at the scheduling entity. Forexample, the resource assignment and scheduling circuitry 941 shown anddescribed above in reference to FIG. 9 may access a transmission optiontable 915 to identify the plurality of transmission options andassociated puncturing patterns.

At block 1506, the scheduling entity may make a scheduling decision forthe at least two consecutive uplink subframes based on the transmissionoptions and associated puncturing patterns for communication of thecodeword in the given subframe. For example, the resource assignment andscheduling circuitry 941 shown and described above in reference to FIG.9 may make the scheduling decision for the at least two consecutivesubframes.

At block 1508, the scheduling entity may determine whether thescheduling decision resulted in the selection of a problematicpuncturing pattern that may hinder decoding of the codeword at thescheduling entity. If the selected puncturing pattern is problematic (Ybranch of block 1508), at block 1510, the scheduling entity may select aturbo decoder running a BCJR algorithm (MAP algorithm) to decode thecodeword received in the given uplink subframe. For example, the ULtraffic and control channel reception and processing circuitry 943 anddecoder 944 may select the turbo decoder running the BCJR algorithm todecode the received codeword.

FIG. 16 is a flow chart illustrating an exemplary process 1600 for ascheduled entity (e.g., UE) to mitigate decoding errors due topuncturing, in accordance with aspects of the present disclosure. Asdescribed below, some or all illustrated features may be omitted in aparticular implementation within the scope of the present disclosure,and some illustrated features may not be required for implementation ofall embodiments. In some examples, the process 1600 may be carried outby the scheduled entity 1000 illustrated in FIG. 10. In some examples,the process 1600 may be carried out by any suitable apparatus or meansfor carrying out the functions or algorithm described below.

At block 1602, the scheduled entity may identify a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS). At block1604, the scheduled entity may identify respective puncturing patternsfor each of the transmission options for at least two consecutivesubframes, each having a same transmission direction. In some examples,the puncturing patterns enable retuning of the scheduled entity from afirst narrowband utilized by the scheduled entity in a first subframe toa second narrowband utilized by the scheduled entity in a secondsubframe. In some examples, one or more of the puncturing patternsassociated with one or more of the transmission options may hinderdecoding of a codeword communicated between the scheduled entity and ascheduling entity within a given subframe of the at least twoconsecutive subframes. For example, the UL traffic and control channelgeneration and transmission circuitry 1042 or the DL traffic and controlchannel reception and processing circuitry 1046, together with thepuncturing circuitry 1044, shown and described above in reference toFIG. 10 may access a transmission option table 1015 to identify theplurality of transmission options and associated puncturing patterns.

At block 1606, the scheduled entity may modify at least one aspect of ascheduling decision associated with communication of the codeword in thegiven subframe, where the scheduling decision utilizes at least aselected transmission option, to reduce decoding errors of the codeword.In some examples, the scheduled entity may modify a puncturing patternor a transport block size of the codeword. For example, the DL trafficand control channel reception and processing circuitry 1046 shown anddescribed above in reference to FIG. 10 may receive a PDCCH includingDCI carrying a downlink assignment or uplink grant indicating thescheduling decision and the UL traffic and control channel generationand transmission circuitry 1042 or the DL traffic and control channelreception and processing circuitry 1046, possibly together with thepuncturing circuitry 1044, shown and described above in reference toFIG. 10, may modify the scheduling decision.

FIG. 17 is a flow chart illustrating an exemplary process 1700 for ascheduled entity (e.g., UE) to mitigate decoding errors due topuncturing, in accordance with aspects of the present disclosure. Asdescribed below, some or all illustrated features may be omitted in aparticular implementation within the scope of the present disclosure,and some illustrated features may not be required for implementation ofall embodiments. In some examples, the process 1700 may be carried outby the scheduled entity 1000 illustrated in FIG. 10. In some examples,the process 1700 may be carried out by any suitable apparatus or meansfor carrying out the functions or algorithm described below.

At block 1702, the scheduled entity may identify a plurality oftransmission options, each including a respective number of resourceblocks and a respective modulation and coding scheme (MCS). At block1704, the scheduled entity may identify respective puncturing patternsfor each of the transmission options for at least two consecutivesubframes, each having a same transmission direction. In some examples,the puncturing patterns enable retuning of the scheduled entity from afirst narrowband utilized by the scheduled entity in a first subframe toa second narrowband utilized by the scheduled entity in a secondsubframe. In some examples, one or more of the puncturing patternsassociated with one or more of the transmission options may hinderdecoding of a codeword communicated between the scheduled entity and ascheduling entity within a given subframe of the at least twoconsecutive subframes. For example, the UL traffic and control channelgeneration and transmission circuitry 1042 or the DL traffic and controlchannel reception and processing circuitry 1046, together with thepuncturing circuitry 1044, shown and described above in reference toFIG. 10 may access a transmission option table 1015 to identify theplurality of transmission options and associated puncturing patterns.

At block 1706, the scheduled entity may identify a selected transmissionoption for communication of the codeword in the given subframe. At block1708, the scheduled entity may further identify a selected puncturingpattern associated with the selected transmission option for puncturingthe codeword. For example, the DL traffic and control channel receptionand processing circuitry 1046 shown and described above in reference toFIG. 10 may receive a PDCCH including DCI carrying a downlink assignmentor uplink grant indicating the selected transmission option and thepuncturing circuitry 1044 shown and described above in reference to FIG.10 may identify a puncturing pattern to utilize for the selectedtransmission option from the transmission options table 1015.

At block 1710, the scheduled entity may determine whether the selectedpuncturing pattern is problematic (e.g., may hinder decoding of thecodeword). If the selected puncturing pattern is problematic (Y branchof block 1710), the process may proceed to either block 1712, block1714, or block 1716. At block 1712, the scheduled entity may modify theselected puncturing pattern to puncture fewer symbols associated withthe codeword. At block 1714, the scheduled entity may modify theselected puncturing pattern to puncture different symbols associatedwith the codeword. For example, the puncturing circuitry 1044 shown anddescribed above in reference to FIG. 10 may modify the puncturingpattern.

At block 1716, for uplink transmissions, the scheduled entity may modifythe transport block size of the codeword. For example, the UL trafficand control channel generation and transmission circuitry 1042 shown anddescribed above in reference to FIG. 10 may utilize the transport blocksize table 1016 to modify the transport block size of the codeword forthe selected transmission option.

Several aspects of a wireless communication network have been presentedwith reference to an exemplary implementation. As those skilled in theart will readily appreciate, various aspects described throughout thisdisclosure may be extended to other telecommunication systems, networkarchitectures and communication standards.

By way of example, various aspects may be implemented within othersystems defined by 3GPP, such as Long-Term Evolution (LTE), the EvolvedPacket System (EPS), the Universal Mobile Telecommunication System(UMTS), and/or the Global System for Mobile (GSM). Various aspects mayalso be extended to systems defined by the 3rd Generation PartnershipProject 2 (3GPP2), such as CDMA2000 and/or Evolution-Data Optimized(EV-DO). Other examples may be implemented within systems employing IEEE802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB),Bluetooth, and/or other suitable systems. The actual telecommunicationstandard, network architecture, and/or communication standard employedwill depend on the specific application and the overall designconstraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean“serving as an example, instance, or illustration.” Any implementationor aspect described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other aspects of thedisclosure. Likewise, the term “aspects” does not require that allaspects of the disclosure include the discussed feature, advantage ormode of operation. The term “coupled” is used herein to refer to thedirect or indirect coupling between two objects. For example, if objectA physically touches object B, and object B touches object C, thenobjects A and C may still be considered coupled to one another—even ifthey do not directly physically touch each other. For instance, a firstobject may be coupled to a second object even though the first object isnever directly physically in contact with the second object. The terms“circuit” and “circuitry” are used broadly, and intended to include bothhardware implementations of electrical devices and conductors that, whenconnected and configured, enable the performance of the functionsdescribed in the present disclosure, without limitation as to the typeof electronic circuits, as well as software implementations ofinformation and instructions that, when executed by a processor, enablethe performance of the functions described in the present disclosure.

One or more of the components, steps, features and/or functionsillustrated in FIGS. 1-17 may be rearranged and/or combined into asingle component, step, feature or function or embodied in severalcomponents, steps, or functions. Additional elements, components, steps,and/or functions may also be added without departing from novel featuresdisclosed herein. The apparatus, devices, and/or components illustratedin FIGS. 1-3, 9 and/or 10 may be configured to perform one or more ofthe methods, features, or steps described herein. The novel algorithmsdescribed herein may also be efficiently implemented in software and/orembedded in hardware.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of exemplary processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112(f) unless the element is expressly recited using the phrase“means for” or, in the case of a method claim, the element is recitedusing the phrase “step for.”

What is claimed is:
 1. A method of wireless communication at ascheduling entity in a wireless communication network, the methodcomprising: identifying a plurality of transmission options, eachcomprising a respective number of resource blocks and a respectivemodulation and coding scheme (MCS); identifying respective puncturingpatterns associated with each of the plurality of transmission optionsfor at least two consecutive subframes, each comprising a sametransmission direction, wherein the respective puncturing patternsassociated with each of the plurality of transmission options enableretuning of the UE from a first narrowband utilized in a first subframeof the at least two consecutive subframes to a second narrowbandutilized in a second subframe of the at least two consecutive subframes;and making a scheduling decision for the at least two consecutivesubframes based on the plurality of transmission options and thepuncturing patterns associated with each of the plurality oftransmission options, wherein the scheduling decision comprises at leasta selected transmission option of the plurality of transmission optionsfor communication of a first codeword between the scheduling entity anda user equipment (UE) in a given subframe of the at least twoconsecutive subframes; wherein making the scheduling decision furthercomprises selecting at least one aspect of the scheduling decision toreduce decoding errors of the first codeword.
 2. The method of claim 1,wherein selecting the at least one aspect of the scheduling decisionfurther comprises: selecting the selected transmission option of theplurality of transmission options for communication of the firstcodeword in the given subframe; selecting a selected puncturing patternof the respective puncturing patterns associated with the selectedtransmission option; and modifying the selected puncturing patternassociated with the selected transmission option for communication ofthe first codeword in the given subframe.
 3. The method of claim 1,further comprising: identifying the first narrowband scheduled for theUE within the first subframe of the at least two consecutive subframesbased on the scheduling decision; and identifying the second narrowbandscheduled for the UE within the second subframe of the at least twoconsecutive subframes based on the scheduling decision, wherein thesecond subframe is immediately subsequent to the first subframe.
 4. Themethod of claim 3, wherein the first subframe comprises the givensubframe and wherein selecting the at least one aspect of the schedulingdecision further comprises: modifying the second narrowband scheduledfor the second subframe to match the first narrowband scheduled for thefirst subframe for communication of the first codeword within the firstsubframe without puncturing of the first codeword.
 5. The method ofclaim 3, wherein the first subframe comprises the given subframe andwherein selecting the at least one aspect of the scheduling decisionfurther comprises: canceling scheduling of a second codeword forcommunication between the scheduling entity and the UE in the secondsubframe to avoid puncturing of the first codeword in the firstsubframe; and rescheduling the second codeword in a subsequent subframesubsequent to the second subframe.
 6. The method of claim 3, wherein thefirst subframe comprises the given subframe and wherein selecting the atleast one aspect of the scheduling decision further comprises: selectingthe selected transmission option of the plurality of transmissionoptions for communication of the first codeword in the first subframe;selecting a selected puncturing pattern of the respective puncturingpatterns associated with the selected transmission option; and modifyinga type of information scheduled for communication between the schedulingentity and the UE in the second subframe to modify the selectedpuncturing pattern to enable decoding of the first codeword.
 7. Themethod of claim 1, wherein selecting the at least one aspect of thescheduling decision further comprises: selecting the selectedtransmission option of the plurality of transmission options forcommunication of the first codeword in the given subframe; selecting aselected puncturing pattern of the respective puncturing patternsassociated with the selected transmission option; and modifying atransport block size associated with the selected transmission optionfor communication of the first codeword within the given subframe toenable decoding of the first codeword.
 8. The method of claim 1, whereinselecting the at least one aspect of the scheduling decision furthercomprises: selecting a turbo decoder running a Bahl-Cocke-Jelinek-Raviv(BCJR) algorithm for decoding of the codeword communicated in the givensubframe.
 9. The method of claim 1, wherein each of the at least twoconsecutive subframes comprise single-carrier frequency divisionmultiple access (SC-FDMA) symbols.
 10. The method of claim 9, whereineach of the at least two consecutive subframes comprises physical uplinkshared channel (PUSCH) SC-FDMA symbols or physical downlink sharedchannel (PDSCH) SC-FDMA symbols.
 11. A scheduling entity within awireless communication network, comprising: a processor; a memorycommunicatively coupled to the processor; and a transceivercommunicatively coupled to the processor, wherein the processor isconfigured to: identify a plurality of transmission options, eachcomprising a respective number of resource blocks and a respectivemodulation and coding scheme (MCS); identify respective puncturingpatterns associated with each of the plurality of transmission optionsfor at least two consecutive subframes, each comprising a sametransmission direction, wherein the respective puncturing patternsassociated with each of the plurality of transmission options enableretuning of the UE from a first narrowband utilized in a first subframeof the at least two consecutive subframes to a second narrowbandutilized in a second subframe of the at least two consecutive subframes;make a scheduling decision for the at least two consecutive subframesbased on the plurality of transmission options and the puncturingpatterns associated with each of the plurality of transmission options,wherein the scheduling decision comprises at least a selectedtransmission option of the plurality of transmission options forcommunication of a first codeword between the scheduling entity and auser equipment (UE) via the transceiver in a given subframe of the atleast two consecutive subframes; and select at least one aspect of thescheduling decision to reduce decoding errors of the first codeword. 12.The scheduling entity of claim 11, wherein the processor is furtherconfigured to: select the selected transmission option of the pluralityof transmission options for communication of the first codeword in thegiven subframe; select a selected puncturing pattern of the respectivepuncturing patterns associated with the selected transmission option;and modify the selected puncturing pattern associated with the selectedtransmission option for communication of the first codeword in the givensubframe.
 13. The scheduling entity of claim 11, wherein the processoris further configured to: identify the first narrowband scheduled forthe UE within the first subframe of the at least two consecutivesubframes based on the scheduling decision; and identify the secondnarrowband scheduled for the UE within the second subframe of the atleast two consecutive subframes based on the scheduling decision,wherein the second subframe is immediately subsequent to the firstsubframe.
 14. The scheduling entity of claim 13, wherein the firstsubframe comprises the given subframe and wherein the processor isfurther configured to: modify the second narrowband scheduled for thesecond subframe to match the first narrowband scheduled for the firstsubframe for communication of the first codeword within the firstsubframe without puncturing of the first codeword.
 15. The schedulingentity of claim 13, wherein the first subframe comprises the givensubframe and wherein the processor is further configured to: cancelscheduling of a second codeword for communication between the schedulingentity and the UE in the second subframe to avoid puncturing of thefirst codeword in the first subframe; and reschedule the second codewordin a subsequent subframe subsequent to the second subframe.
 16. Thescheduling entity of claim 13, wherein the first subframe comprises thegiven subframe and wherein the processor is further configured to:select the selected transmission option of the plurality of transmissionoptions for communication of the first codeword in the first subframe;select a selected puncturing pattern of the respective puncturingpatterns associated with the selected transmission option; and modify atype of information scheduled for communication between the schedulingentity and the UE in the second subframe to modify the selectedpuncturing pattern to enable decoding of the first codeword.
 17. Thescheduling entity of claim 11, wherein the processor is furtherconfigured to: select the selected transmission option of the pluralityof transmission options for communication of the first codeword in thegiven subframe; select a selected puncturing pattern of the respectivepuncturing patterns associated with the selected transmission option;and modify a transport block size associated with the selectedtransmission option for communication of the first codeword within thegiven subframe to enable decoding of the first codeword.
 18. Thescheduling entity of claim 11, wherein the processor is furtherconfigured to: select a turbo decoder running a Bahl-Cocke-Jelinek-Raviv(BCJR) algorithm for decoding of the codeword communicated in the givensubframe.
 19. A method of wireless communication at a scheduled entityin wireless communication with a scheduling entity in a wirelesscommunication network, the method comprising: identifying a plurality oftransmission options, each comprising a respective number of resourceblocks and a respective modulation and coding scheme (MCS); identifyingrespective puncturing patterns associated with each of the plurality oftransmission options for at least two consecutive subframes, eachcomprising a same transmission direction, wherein the respectivepuncturing patterns associated with each of the plurality oftransmission options enable retuning of the UE from a first narrowbandutilized in a first subframe of the at least two consecutive subframesto a second narrowband utilized in a second subframe of the at least twoconsecutive subframes; and modifying at least one aspect of a schedulingdecision associated with communication of a codeword between thescheduling entity and the scheduled entity in a given subframe of the atleast two consecutive subframes utilizing a selected transmission optionof the plurality of transmission options to reduce decoding errors ofthe codeword; wherein the at least one aspect comprises at least one ofa selected puncturing pattern of the respective puncturing patternsassociated with the selected transmission option or a transport blocksize associated with the codeword.
 20. The method of claim 19, whereinmodifying the at least one aspect of the scheduling decision furthercomprises: identifying the selected puncturing pattern of the respectivepuncturing patterns associated with the selected transmission option;and modifying the selected puncturing pattern to puncture fewer symbolsin the codeword communicated in the given subframe.
 21. The method ofclaim 19, wherein modifying at least one aspect of the schedulingdecision further comprises: identifying the selected puncturing patternof the respective puncturing patterns associated with the selectedtransmission option; and modifying the selected puncturing pattern topuncture different symbols in the codeword communicated in the givensubframe.
 22. The method of claim 19, wherein modifying the at least oneaspect of the scheduling decision further comprises: identifying theselected puncturing pattern of the respective puncturing patternsassociated with the selected transmission option; and modifying thetransport block size associated with the selected transmission optionfor communication of the first codeword within the given subframe toenable decoding of the first codeword, wherein the at least twoconsecutive subframes comprise uplink subframes.
 23. A user equipment inwireless communication with a scheduling entity within a wirelesscommunication network, comprising: a processor; a memory communicativelycoupled to the processor; and a transceiver communicatively coupled tothe processor, wherein the processor is configured to: identify aplurality of transmission options, each comprising a respective numberof resource blocks and a respective modulation and coding scheme (MCS);identify respective puncturing patterns associated with each of theplurality of transmission options for at least two consecutivesubframes, each comprising a same transmission direction, wherein therespective puncturing patterns associated with each of the plurality oftransmission options enable retuning of the UE from a first narrowbandutilized in a first subframe of the at least two consecutive subframesto a second narrowband utilized in a second subframe of the at least twoconsecutive subframes; and modify at least one aspect of a schedulingdecision associated with communication of a codeword between thescheduling entity and the user equipment via the transceiver in a givensubframe of the at least two consecutive subframes utilizing a selectedtransmission option of the plurality of transmission options to reducedecoding errors of the codeword; wherein the at least one aspectcomprises at least one of a selected puncturing pattern of therespective puncturing patterns associated with the selected transmissionoption or a transport block size associated with the codeword.
 24. Theuser equipment of claim 23, wherein the processor is further configuredto: identify the selected puncturing pattern of the respectivepuncturing patterns associated with the selected transmission option;and modify the selected puncturing pattern to puncture fewer symbols inthe codeword communicated in the given subframe.
 25. The user equipmentof claim 23, wherein the processor is further configured to: identify aselected puncturing pattern of the respective puncturing patternsassociated with the selected transmission option; and modify theselected puncturing pattern to puncture different symbols in thecodeword communicated in the given subframe.
 26. The user equipment ofclaim 23, wherein the processor is further configured to: identify aselected puncturing pattern of the respective puncturing patternsassociated with the selected transmission option; and modify thetransport block size associated with the selected transmission optionfor communication of the first codeword within the given subframe toenable decoding of the codeword, wherein the at least two consecutivesubframes comprise uplink subframes.